query tuning - Page 328

datesub question

- by Ahmet vardar

Hi, is it possible to use date_sub like this ? $dt = date("Y-m-d h:i:s"); $query = "INSERT INTO `table` (`date`) VALUES ('DATE_SUB('$dt', INTERVAL 15 DAY)')"; $result = MYSQL_QUERY($query); Thanks

SQL Command Not Properly Ended (Nested Aggregation with Group-by)

I keep getting this error when I tried to execute this query, although I couldn't figure out what went wrong. I'm using Oracle and JDBC. Here's the query: SELECT Temp.flight_number, Temp.avgprice FROM (SELECT P.flight_number, AVG (P.amount) AS avgprice FROM purchase P GROUP BY P.flight_number) AS Temp WHERE Temp.avgprice = (SELECT MAX (Temp.avgprice) FROM Temp) I'm trying to get the maximum of average price of the tickets that customers have booked, group by flight_number.

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Doing sum's if certain conditions are true

- by Gugu

I am trying to build a query that does a sum if a certain parameter is set. For example: SELECT SUM(IF(<condition>,field,field)) AS total_value ...which is working correctly. But i have more than one condition in IF(), like: SELECT SUM(IF(<condition> <condition>,field,field)) AS total_value ..which is not working, could you have any idea what should be the right query for this.

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php fetch user data from mysql

- by milodinosaur

hi, currently i have 2 table in mysql structure: messages id | content | user_id | time submessages id | subcontent | msg_id | user_id | time submessages msg_id is FK for messages id. Now i need to query from php $cur_user = $user->current; // current user id. SELECT * FROM messages WHERE id > '{$_GET['id']}' // problem here how do i query submessages that posted by others not include current user? thank you.

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Mysql Count

- by Buda

I have the following query: select MIN(q.a), * FROM ( sub-query1 ) as q UNION sub-query2 How can I return the number of elements in query1 as a row of master-query? If i use count (*) i´ve only the count CountElementSub-Query1 i need some like that rowA, rowB, rowC, CountElementSub-Query1 rowA, rowB, rowC, CountElementSub-Query1 rowA, rowB, rowC, CountElementSub-Query1 rowA, rowB, rowC, CountElementSub-Query1

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Sorting by value with ORDER BY?

- by Kevin

For clarification, are you able to use MySQL this way to sort? ORDER BY CompanyID = XXX DESC What I am trying to do is use one sql query to sort everything where X = Y, in this case, where CompanyID = XXX. All values where CompanyID is not XXX should come after all the results where CompanyID = XXX. I don't want to limit my query but I do want to sort a particular company above other listings.

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Does COUNT(*) always return a result?

- by Click Upvote

If a do a query such as: SELECT COUNT(*) as num FROM table WHERE x = 'y' Will it always return a result, even when the query doesn't match any record? Or do i need to validate and make sure a row is returned as the result?

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Differences Between NHibernate and Entity Framework

- by Ricardo Peres

Introduction NHibernate and Entity Framework are two of the most popular O/RM frameworks on the .NET world. Although they share some functionality, there are some aspects on which they are quite different. This post will describe this differences and will hopefully help you get started with the one you know less. Mind you, this is a personal selection of features to compare, it is by no way an exhaustive list. History First, a bit of history. NHibernate is an open-source project that was first ported from Java’s venerable Hibernate framework, one of the first O/RM frameworks, but nowadays it is not tied to it, for example, it has .NET specific features, and has evolved in different ways from those of its Java counterpart. Current version is 3.3, with 3.4 on the horizon. It currently targets .NET 3.5, but can be used as well in .NET 4, it only makes no use of any of its specific functionality. You can find its home page at NHForge. Entity Framework 1 came out with .NET 3.5 and is now on its second major version, despite being version 4. Code First sits on top of it and but came separately and will also continue to be released out of line with major .NET distributions. It is currently on version 4.3.1 and version 5 will be released together with .NET Framework 4.5. All versions will target the current version of .NET, at the time of their release. Its home location is located at MSDN. Architecture In NHibernate, there is a separation between the Unit of Work and the configuration and model instances. You start off by creating a Configuration object, where you specify all global NHibernate settings such as the database and dialect to use, the batch sizes, the mappings, etc, then you build an ISessionFactory from it. The ISessionFactory holds model and metadata that is tied to a particular database and to the settings that came from the Configuration object, and, there will typically be only one instance of each in a process. Finally, you create instances of ISession from the ISessionFactory, which is the NHibernate representation of the Unit of Work and Identity Map. This is a lightweight object, it basically opens and closes a database connection as required and keeps track of the entities associated with it. ISession objects are cheap to create and dispose, because all of the model complexity is stored in the ISessionFactory and Configuration objects. As for Entity Framework, the ObjectContext/DbContext holds the configuration, model and acts as the Unit of Work, holding references to all of the known entity instances. This class is therefore not lightweight as its NHibernate counterpart and it is not uncommon to see examples where an instance is cached on a field. Mappings Both NHibernate and Entity Framework (Code First) support the use of POCOs to represent entities, no base classes are required (or even possible, in the case of NHibernate). As for mapping to and from the database, NHibernate supports three types of mappings: XML-based, which have the advantage of not tying the entity classes to a particular O/RM; the XML files can be deployed as files on the file system or as embedded resources in an assembly; Attribute-based, for keeping both the entities and database details on the same place at the expense of polluting the entity classes with NHibernate-specific attributes; Strongly-typed code-based, which allows dynamic creation of the model and strongly typing it, so that if, for example, a property name changes, the mapping will also be updated. Entity Framework can use: Attribute-based (although attributes cannot express all of the available possibilities – for example, cascading); Strongly-typed code mappings. Database Support With NHibernate you can use mostly any database you want, including: SQL Server; SQL Server Compact; SQL Server Azure; Oracle; DB2; PostgreSQL; MySQL; Sybase Adaptive Server/SQL Anywhere; Firebird; SQLLite; Informix; Any through OLE DB; Any through ODBC. Out of the box, Entity Framework only supports SQL Server, but a number of providers exist, both free and commercial, for some of the most used databases, such as Oracle and MySQL. See a list here. Inheritance Strategies Both NHibernate and Entity Framework support the three canonical inheritance strategies: Table Per Type Hierarchy (Single Table Inheritance), Table Per Type (Class Table Inheritance) and Table Per Concrete Type (Concrete Table Inheritance). Associations Regarding associations, both support one to one, one to many and many to many. However, NHibernate offers far more collection types: Bags of entities or values: unordered, possibly with duplicates; Lists of entities or values: ordered, indexed by a number column; Maps of entities or values: indexed by either an entity or any value; Sets of entities or values: unordered, no duplicates; Arrays of entities or values: indexed, immutable. Querying NHibernate exposes several querying APIs: LINQ is probably the most used nowadays, and really does not need to be introduced; Hibernate Query Language (HQL) is a database-agnostic, object-oriented SQL-alike language that exists since NHibernate’s creation and still offers the most advanced querying possibilities; well suited for dynamic queries, even if using string concatenation; Criteria API is an implementation of the Query Object pattern where you create a semi-abstract conceptual representation of the query you wish to execute by means of a class model; also a good choice for dynamic querying; Query Over offers a similar API to Criteria, but using strongly-typed LINQ expressions instead of strings; for this, although more refactor-friendlier that Criteria, it is also less suited for dynamic queries; SQL, including stored procedures, can also be used; Integration with Lucene.NET indexer is available. As for Entity Framework: LINQ to Entities is fully supported, and its implementation is considered very complete; it is the API of choice for most developers; Entity-SQL, HQL’s counterpart, is also an object-oriented, database-independent querying language that can be used for dynamic queries; SQL, of course, is also supported. Caching Both NHibernate and Entity Framework, of course, feature first-level cache. NHibernate also supports a second-level cache, that can be used among multiple ISessionFactorys, even in different processes/machines: Hashtable (in-memory); SysCache (uses ASP.NET as the cache provider); SysCache2 (same as above but with support for SQL Server SQL Dependencies); Prevalence; SharedCache; Memcached; Redis; NCache; Appfabric Caching. Out of the box, Entity Framework does not have any second-level cache mechanism, however, there are some public samples that show how we can add this. ID Generators NHibernate supports different ID generation strategies, coming from the database and otherwise: Identity (for SQL Server, MySQL, and databases who support identity columns); Sequence (for Oracle, PostgreSQL, and others who support sequences); Trigger-based; HiLo; Sequence HiLo (for databases that support sequences); Several GUID flavors, both in GUID as well as in string format; Increment (for single-user uses); Assigned (must know what you’re doing); Sequence-style (either uses an actual sequence or a single-column table); Table of ids; Pooled (similar to HiLo but stores high values in a table); Native (uses whatever mechanism the current database supports, identity or sequence). Entity Framework only supports: Identity generation; GUIDs; Assigned values. Properties NHibernate supports properties of entity types (one to one or many to one), collections (one to many or many to many) as well as scalars and enumerations. It offers a mechanism for having complex property types generated from the database, which even include support for querying. It also supports properties originated from SQL formulas. Entity Framework only supports scalars, entity types and collections. Enumerations support will come in the next version. Events and Interception NHibernate has a very rich event model, that exposes more than 20 events, either for synchronous pre-execution or asynchronous post-execution, including: Pre/Post-Load; Pre/Post-Delete; Pre/Post-Insert; Pre/Post-Update; Pre/Post-Flush. It also features interception of class instancing and SQL generation. As for Entity Framework, only two events exist: ObjectMaterialized (after loading an entity from the database); SavingChanges (before saving changes, which include deleting, inserting and updating). Tracking Changes For NHibernate as well as Entity Framework, all changes are tracked by their respective Unit of Work implementation. Entities can be attached and detached to it, Entity Framework does, however, also support self-tracking entities. Optimistic Concurrency Control NHibernate supports all of the imaginable scenarios: SQL Server’s ROWVERSION; Oracle’s ORA_ROWSCN; A column containing date and time; A column containing a version number; All/dirty columns comparison. Entity Framework is more focused on Entity Framework, so it only supports: SQL Server’s ROWVERSION; Comparing all/some columns. Batching NHibernate has full support for insertion batching, but only if the ID generator in use is not database-based (for example, it cannot be used with Identity), whereas Entity Framework has no batching at all. Cascading Both support cascading for collections and associations: when an entity is deleted, their conceptual children are also deleted. NHibernate also offers the possibility to set the foreign key column on children to NULL instead of removing them. Flushing Changes NHibernate’s ISession has a FlushMode property that can have the following values: Auto: changes are sent to the database when necessary, for example, if there are dirty instances of an entity type, and a query is performed against this entity type, or if the ISession is being disposed; Commit: changes are sent when committing the current transaction; Never: changes are only sent when explicitly calling Flush(). As for Entity Framework, changes have to be explicitly sent through a call to AcceptAllChanges()/SaveChanges(). Lazy Loading NHibernate supports lazy loading for Associated entities (one to one, many to one); Collections (one to many, many to many); Scalar properties (thing of BLOBs or CLOBs). Entity Framework only supports lazy loading for: Associated entities; Collections. Generating and Updating the Database Both NHibernate and Entity Framework Code First (with the Migrations API) allow creating the database model from the mapping and updating it if the mapping changes. Extensibility As you can guess, NHibernate is far more extensible than Entity Framework. Basically, everything can be extended, from ID generation, to LINQ to SQL transformation, HQL native SQL support, custom column types, custom association collections, SQL generation, supported databases, etc. With Entity Framework your options are more limited, at least, because practically no information exists as to what can be extended/changed. It features a provider model that can be extended to support any database. Integration With Other Microsoft APIs and Tools When it comes to integration with Microsoft technologies, it will come as no surprise that Entity Framework offers the best support. For example, the following technologies are fully supported: ASP.NET (through the EntityDataSource); ASP.NET Dynamic Data; WCF Data Services; WCF RIA Services; Visual Studio (through the integrated designer). Documentation This is another point where Entity Framework is superior: NHibernate lacks, for starters, an up to date API reference synchronized with its current version. It does have a community mailing list, blogs and wikis, although not much used. Entity Framework has a number of resources on MSDN and, of course, several forums and discussion groups exist. Conclusion Like I said, this is a personal list. I may come as a surprise to some that Entity Framework is so behind NHibernate in so many aspects, but it is true that NHibernate is much older and, due to its open-source nature, is not tied to product-specific timeframes and can thus evolve much more rapidly. I do like both, and I chose whichever is best for the job I have at hands. I am looking forward to the changes in EF5 which will add significant value to an already interesting product. So, what do you think? Did I forget anything important or is there anything else worth talking about? Looking forward for your comments!

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Node.js Adventure - When Node Flying in Wind

- by Shaun

In the first post of this series I mentioned some popular modules in the community, such as underscore, async, etc.. I also listed a module named “Wind (zh-CN)”, which is created by one of my friend, Jeff Zhao (zh-CN). Now I would like to use a separated post to introduce this module since I feel it brings a new async programming style in not only Node.js but JavaScript world. If you know or heard about the new feature in C# 5.0 called “async and await”, or you learnt F#, you will find the “Wind” brings the similar async programming experience in JavaScript. By using “Wind”, we can write async code that looks like the sync code. The callbacks, async stats and exceptions will be handled by “Wind” automatically and transparently. What’s the Problem: Dense “Callback” Phobia Let’s firstly back to my second post in this series. As I mentioned in that post, when we wanted to read some records from SQL Server we need to open the database connection, and then execute the query. In Node.js all IO operation are designed as async callback pattern which means when the operation was done, it will invoke a function which was taken from the last parameter. For example the database connection opening code would be like this. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: } 8: }); And then if we need to query the database the code would be like this. It nested in the previous function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: } 14: }; 15: } 16: }); Assuming if we need to copy some data from this database to another then we need to open another connection and execute the command within the function under the query function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: target.open(targetConnectionString, function(error, t_conn) { 14: if(error) { 15: // connect failed 16: } 17: else { 18: t_conn.queryRaw(copy_command, function(error, results) { 19: if(error) { 20: // copy failed 21: } 22: else { 23: // and then, what do you want to do now... 24: } 25: }; 26: } 27: }; 28: } 29: }; 30: } 31: }); This is just an example. In the real project the logic would be more complicated. This means our application might be messed up and the business process will be fragged by many callback functions. I would like call this “Dense Callback Phobia”. This might be a challenge how to make code straightforward and easy to read, something like below. 1: try 2: { 3: // open source connection 4: var s_conn = sqlConnect(s_connectionString); 5: // retrieve data 6: var results = sqlExecuteCommand(s_conn, s_command); 7: 8: // open target connection 9: var t_conn = sqlConnect(t_connectionString); 10: // prepare the copy command 11: var t_command = getCopyCommand(results); 12: // execute the copy command 13: sqlExecuteCommand(s_conn, t_command); 14: } 15: catch (ex) 16: { 17: // error handling 18: } What’s the Problem: Sync-styled Async Programming Similar as the previous problem, the callback-styled async programming model makes the upcoming operation as a part of the current operation, and mixed with the error handling code. So it’s very hard to understand what on earth this code will do. And since Node.js utilizes non-blocking IO mode, we cannot invoke those operations one by one, as they will be executed concurrently. For example, in this post when I tried to copy the records from Windows Azure SQL Database (a.k.a. WASD) to Windows Azure Table Storage, if I just insert the data into table storage one by one and then print the “Finished” message, I will see the message shown before the data had been copied. This is because all operations were executed at the same time. In order to make the copy operation and print operation executed synchronously I introduced a module named “async” and the code was changed as below. 1: async.forEach(results.rows, 2: function (row, callback) { 3: var resource = { 4: "PartitionKey": row[1], 5: "RowKey": row[0], 6: "Value": row[2] 7: }; 8: client.insertEntity(tableName, resource, function (error) { 9: if (error) { 10: callback(error); 11: } 12: else { 13: console.log("entity inserted."); 14: callback(null); 15: } 16: }); 17: }, 18: function (error) { 19: if (error) { 20: error["target"] = "insertEntity"; 21: res.send(500, error); 22: } 23: else { 24: console.log("all done."); 25: res.send(200, "Done!"); 26: } 27: }); It ensured that the “Finished” message will be printed when all table entities had been inserted. But it cannot promise that the records will be inserted in sequence. It might be another challenge to make the code looks like in sync-style? 1: try 2: { 3: forEach(row in rows) { 4: var entity = { /* ... */ }; 5: tableClient.insert(tableName, entity); 6: } 7: 8: console.log("Finished"); 9: } 10: catch (ex) { 11: console.log(ex); 12: } How “Wind” Helps “Wind” is a JavaScript library which provides the control flow with plain JavaScript for asynchronous programming (and more) without additional pre-compiling steps. It’s available in NPM so that we can install it through “npm install wind”. Now let’s create a very simple Node.js application as the example. This application will take some website URLs from the command arguments and tried to retrieve the body length and print them in console. Then at the end print “Finish”. I’m going to use “request” module to make the HTTP call simple so I also need to install by the command “npm install request”. The code would be like this. 1: var request = require("request"); 2: 3: // get the urls from arguments, the first two arguments are `node.exe` and `fetch.js` 4: var args = process.argv.splice(2); 5: 6: // main function 7: var main = function() { 8: for(var i = 0; i < args.length; i++) { 9: // get the url 10: var url = args[i]; 11: // send the http request and try to get the response and body 12: request(url, function(error, response, body) { 13: if(!error && response.statusCode == 200) { 14: // log the url and the body length 15: console.log( 16: "%s: %d.", 17: response.request.uri.href, 18: body.length); 19: } 20: else { 21: // log error 22: console.log(error); 23: } 24: }); 25: } 26: 27: // finished 28: console.log("Finished"); 29: }; 30: 31: // execute the main function 32: main(); Let’s execute this application. (I made them in multi-lines for better reading.) 1: node fetch.js 2: "http://www.igt.com/us-en.aspx" 3: "http://www.igt.com/us-en/games.aspx" 4: "http://www.igt.com/us-en/cabinets.aspx" 5: "http://www.igt.com/us-en/systems.aspx" 6: "http://www.igt.com/us-en/interactive.aspx" 7: "http://www.igt.com/us-en/social-gaming.aspx" 8: "http://www.igt.com/support.aspx" Below is the output. As you can see the finish message was printed at the beginning, and the pages’ length retrieved in a different order than we specified. This is because in this code the request command, console logging command are executed asynchronously and concurrently. Now let’s introduce “Wind” to make them executed in order, which means it will request the websites one by one, and print the message at the end. First of all we need to import the “Wind” package and make sure the there’s only one global variant named “Wind”, and ensure it’s “Wind” instead of “wind”. 1: var Wind = require("wind"); Next, we need to tell “Wind” which code will be executed asynchronously so that “Wind” can control the execution process. In this case the “request” operation executed asynchronously so we will create a “Task” by using a build-in helps function in “Wind” named Wind.Async.Task.create. 1: var requestBodyLengthAsync = function(url) { 2: return Wind.Async.Task.create(function(t) { 3: request(url, function(error, response, body) { 4: if(error || response.statusCode != 200) { 5: t.complete("failure", error); 6: } 7: else { 8: var data = 9: { 10: uri: response.request.uri.href, 11: length: body.length 12: }; 13: t.complete("success", data); 14: } 15: }); 16: }); 17: }; The code above created a “Task” from the original request calling code. In “Wind” a “Task” means an operation will be finished in some time in the future. A “Task” can be started by invoke its start() method, but no one knows when it actually will be finished. The Wind.Async.Task.create helped us to create a task. The only parameter is a function where we can put the actual operation in, and then notify the task object it’s finished successfully or failed by using the complete() method. In the code above I invoked the request method. If it retrieved the response successfully I set the status of this task as “success” with the URL and body length. If it failed I set this task as “failure” and pass the error out. Next, we will change the main() function. In “Wind” if we want a function can be controlled by Wind we need to mark it as “async”. This should be done by using the code below. 1: var main = eval(Wind.compile("async", function() { 2: })); When the application is running, Wind will detect “eval(Wind.compile(“async”, function” and generate an anonymous code from the body of this original function. Then the application will run the anonymous code instead of the original one. In our example the main function will be like this. 1: var main = eval(Wind.compile("async", function() { 2: for(var i = 0; i < args.length; i++) { 3: try 4: { 5: var result = $await(requestBodyLengthAsync(args[i])); 6: console.log( 7: "%s: %d.", 8: result.uri, 9: result.length); 10: } 11: catch (ex) { 12: console.log(ex); 13: } 14: } 15: 16: console.log("Finished"); 17: })); As you can see, when I tried to request the URL I use a new command named “$await”. It tells Wind, the operation next to $await will be executed asynchronously, and the main thread should be paused until it finished (or failed). So in this case, my application will be pause when the first response was received, and then print its body length, then try the next one. At the end, print the finish message. Finally, execute the main function. The full code would be like this. 1: var request = require("request"); 2: var Wind = require("wind"); 3: 4: var args = process.argv.splice(2); 5: 6: var requestBodyLengthAsync = function(url) { 7: return Wind.Async.Task.create(function(t) { 8: request(url, function(error, response, body) { 9: if(error || response.statusCode != 200) { 10: t.complete("failure", error); 11: } 12: else { 13: var data = 14: { 15: uri: response.request.uri.href, 16: length: body.length 17: }; 18: t.complete("success", data); 19: } 20: }); 21: }); 22: }; 23: 24: var main = eval(Wind.compile("async", function() { 25: for(var i = 0; i < args.length; i++) { 26: try 27: { 28: var result = $await(requestBodyLengthAsync(args[i])); 29: console.log( 30: "%s: %d.", 31: result.uri, 32: result.length); 33: } 34: catch (ex) { 35: console.log(ex); 36: } 37: } 38: 39: console.log("Finished"); 40: })); 41: 42: main().start(); Run our new application. At the beginning we will see the compiled and generated code by Wind. Then we can see the pages were requested one by one, and at the end the finish message was printed. Below is the code Wind generated for us. As you can see the original code, the output code were shown. 1: // Original: 2: function () { 3: for(var i = 0; i < args.length; i++) { 4: try 5: { 6: var result = $await(requestBodyLengthAsync(args[i])); 7: console.log( 8: "%s: %d.", 9: result.uri, 10: result.length); 11: } 12: catch (ex) { 13: console.log(ex); 14: } 15: } 16: 17: console.log("Finished"); 18: } 19: 20: // Compiled: 21: /* async << function () { */ (function () { 22: var _builder_$0 = Wind.builders["async"]; 23: return _builder_$0.Start(this, 24: _builder_$0.Combine( 25: _builder_$0.Delay(function () { 26: /* var i = 0; */ var i = 0; 27: /* for ( */ return _builder_$0.For(function () { 28: /* ; i < args.length */ return i < args.length; 29: }, function () { 30: /* ; i ++) { */ i ++; 31: }, 32: /* try { */ _builder_$0.Try( 33: _builder_$0.Delay(function () { 34: /* var result = $await(requestBodyLengthAsync(args[i])); */ return _builder_$0.Bind(requestBodyLengthAsync(args[i]), function (result) { 35: /* console.log("%s: %d.", result.uri, result.length); */ console.log("%s: %d.", result.uri, result.length); 36: return _builder_$0.Normal(); 37: }); 38: }), 39: /* } catch (ex) { */ function (ex) { 40: /* console.log(ex); */ console.log(ex); 41: return _builder_$0.Normal(); 42: /* } */ }, 43: null 44: ) 45: /* } */ ); 46: }), 47: _builder_$0.Delay(function () { 48: /* console.log("Finished"); */ console.log("Finished"); 49: return _builder_$0.Normal(); 50: }) 51: ) 52: ); 53: /* } */ }) How Wind Works Someone may raise a big concern when you find I utilized “eval” in my code. Someone may assume that Wind utilizes “eval” to execute some code dynamically while “eval” is very low performance. But I would say, Wind does NOT use “eval” to run the code. It only use “eval” as a flag to know which code should be compiled at runtime. When the code was firstly been executed, Wind will check and find “eval(Wind.compile(“async”, function”. So that it knows this function should be compiled. Then it utilized parse-js to analyze the inner JavaScript and generated the anonymous code in memory. Then it rewrite the original code so that when the application was running it will use the anonymous one instead of the original one. Since the code generation was done at the beginning of the application was started, in the future no matter how long our application runs and how many times the async function was invoked, it will use the generated code, no need to generate again. So there’s no significant performance hurt when using Wind. Wind in My Previous Demo Let’s adopt Wind into one of my previous demonstration and to see how it helps us to make our code simple, straightforward and easy to read and understand. In this post when I implemented the functionality that copied the records from my WASD to table storage, the logic would be like this. 1, Open database connection. 2, Execute a query to select all records from the table. 3, Recreate the table in Windows Azure table storage. 4, Create entities from each of the records retrieved previously, and then insert them into table storage. 5, Finally, show message as the HTTP response. But as the image below, since there are so many callbacks and async operations, it’s very hard to understand my logic from the code. Now let’s use Wind to rewrite our code. First of all, of course, we need the Wind package. Then we need to include the package files into project and mark them as “Copy always”. Add the Wind package into the source code. Pay attention to the variant name, you must use “Wind” instead of “wind”. 1: var express = require("express"); 2: var async = require("async"); 3: var sql = require("node-sqlserver"); 4: var azure = require("azure"); 5: var Wind = require("wind"); Now we need to create some async functions by using Wind. All async functions should be wrapped so that it can be controlled by Wind which are open database, retrieve records, recreate table (delete and create) and insert entity in table. Below are these new functions. All of them are created by using Wind.Async.Task.create. 1: sql.openAsync = function (connectionString) { 2: return Wind.Async.Task.create(function (t) { 3: sql.open(connectionString, function (error, conn) { 4: if (error) { 5: t.complete("failure", error); 6: } 7: else { 8: t.complete("success", conn); 9: } 10: }); 11: }); 12: }; 13: 14: sql.queryAsync = function (conn, query) { 15: return Wind.Async.Task.create(function (t) { 16: conn.queryRaw(query, function (error, results) { 17: if (error) { 18: t.complete("failure", error); 19: } 20: else { 21: t.complete("success", results); 22: } 23: }); 24: }); 25: }; 26: 27: azure.recreateTableAsync = function (tableName) { 28: return Wind.Async.Task.create(function (t) { 29: client.deleteTable(tableName, function (error, successful, response) { 30: console.log("delete table finished"); 31: client.createTableIfNotExists(tableName, function (error, successful, response) { 32: console.log("create table finished"); 33: if (error) { 34: t.complete("failure", error); 35: } 36: else { 37: t.complete("success", null); 38: } 39: }); 40: }); 41: }); 42: }; 43: 44: azure.insertEntityAsync = function (tableName, entity) { 45: return Wind.Async.Task.create(function (t) { 46: client.insertEntity(tableName, entity, function (error, entity, response) { 47: if (error) { 48: t.complete("failure", error); 49: } 50: else { 51: t.complete("success", null); 52: } 53: }); 54: }); 55: }; Then in order to use these functions we will create a new function which contains all steps for data copying. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: } 4: catch (ex) { 5: console.log(ex); 6: res.send(500, "Internal error."); 7: } 8: })); Let’s execute steps one by one with the “$await” keyword introduced by Wind so that it will be invoked in sequence. First is to open the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: } 7: catch (ex) { 8: console.log(ex); 9: res.send(500, "Internal error."); 10: } 11: })); Then retrieve all records from the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: } 10: catch (ex) { 11: console.log(ex); 12: res.send(500, "Internal error."); 13: } 14: })); After recreated the table, we need to create the entities and insert them into table storage. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: } 24: } 25: catch (ex) { 26: console.log(ex); 27: res.send(500, "Internal error."); 28: } 29: })); Finally, send response back to the browser. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: // send response 24: console.log("all done"); 25: res.send(200, "All done!"); 26: } 27: } 28: catch (ex) { 29: console.log(ex); 30: res.send(500, "Internal error."); 31: } 32: })); If we compared with the previous code we will find now it became more readable and much easy to understand. It’s very easy to know what this function does even though without any comments. When user go to URL “/was/copyRecords” we will execute the function above. The code would be like this. 1: app.get("/was/copyRecords", function (req, res) { 2: copyRecords(req, res).start(); 3: }); And below is the logs printed in local compute emulator console. As we can see the functions executed one by one and then finally the response back to me browser. Scaffold Functions in Wind Wind provides not only the async flow control and compile functions, but many scaffold methods as well. We can build our async code more easily by using them. I’m going to introduce some basic scaffold functions here. In the code above I created some functions which wrapped from the original async function such as open database, create table, etc.. All of them are very similar, created a task by using Wind.Async.Task.create, return error or result object through Task.complete function. In fact, Wind provides some functions for us to create task object from the original async functions. If the original async function only has a callback parameter, we can use Wind.Async.Binding.fromCallback method to get the task object directly. For example the code below returned the task object which wrapped the file exist check function. 1: var Wind = require("wind"); 2: var fs = require("fs"); 3: 4: fs.existsAsync = Wind.Async.Binding.fromCallback(fs.exists); In Node.js a very popular async function pattern is that, the first parameter in the callback function represent the error object, and the other parameters is the return values. In this case we can use another build-in function in Wind named Wind.Async.Binding.fromStandard. For example, the open database function can be created from the code below. 1: sql.openAsync = Wind.Async.Binding.fromStandard(sql.open); 2: 3: /* 4: sql.openAsync = function (connectionString) { 5: return Wind.Async.Task.create(function (t) { 6: sql.open(connectionString, function (error, conn) { 7: if (error) { 8: t.complete("failure", error); 9: } 10: else { 11: t.complete("success", conn); 12: } 13: }); 14: }); 15: }; 16: */ When I was testing the scaffold functions under Wind.Async.Binding I found for some functions, such as the Azure SDK insert entity function, cannot be processed correctly. So I personally suggest writing the wrapped method manually. Another scaffold method in Wind is the parallel tasks coordination. In this example, the steps of open database, retrieve records and recreated table should be invoked one by one, but it can be executed in parallel when copying data from database to table storage. In Wind there’s a scaffold function named Task.whenAll which can be used here. Task.whenAll accepts a list of tasks and creates a new task. It will be returned only when all tasks had been completed, or any errors occurred. For example in the code below I used the Task.whenAll to make all copy operation executed at the same time. 1: var copyRecordsInParallel = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage in parallal 14: var tasks = new Array(results.rows.length); 15: for (var i = 0; i < results.rows.length; i++) { 16: var entity = { 17: "PartitionKey": results.rows[i][1], 18: "RowKey": results.rows[i][0], 19: "Value": results.rows[i][2] 20: }; 21: tasks[i] = azure.insertEntityAsync(tableName, entity); 22: } 23: $await(Wind.Async.Task.whenAll(tasks)); 24: // send response 25: console.log("all done"); 26: res.send(200, "All done!"); 27: } 28: } 29: catch (ex) { 30: console.log(ex); 31: res.send(500, "Internal error."); 32: } 33: })); 34: 35: app.get("/was/copyRecordsInParallel", function (req, res) { 36: copyRecordsInParallel(req, res).start(); 37: }); Besides the task creation and coordination, Wind supports the cancellation solution so that we can send the cancellation signal to the tasks. It also includes exception solution which means any exceptions will be reported to the caller function. Summary In this post I introduced a Node.js module named Wind, which created by my friend Jeff Zhao. As you can see, different from other async library and framework, adopted the idea from F# and C#, Wind utilizes runtime code generation technology to make it more easily to write async, callback-based functions in a sync-style way. By using Wind there will be almost no callback, and the code will be very easy to understand. Currently Wind is still under developed and improved. There might be some problems but the author, Jeff, should be very happy and enthusiastic to learn your problems, feedback, suggestion and comments. You can contact Jeff by - Email: [email protected] - Group: https://groups.google.com/d/forum/windjs - GitHub: https://github.com/JeffreyZhao/wind/issues Source code can be download here. Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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Passing multiple POST parameters to Web API Controller Methods

- by Rick Strahl

ASP.NET Web API introduces a new API for creating REST APIs and making AJAX callbacks to the server. This new API provides a host of new great functionality that unifies many of the features of many of the various AJAX/REST APIs that Microsoft created before it - ASP.NET AJAX, WCF REST specifically - and combines them into a whole more consistent API. Web API addresses many of the concerns that developers had with these older APIs, namely that it was very difficult to build consistent REST style resource APIs easily. While Web API provides many new features and makes many scenarios much easier, a lot of the focus has been on making it easier to build REST compliant APIs that are focused on resource based solutions and HTTP verbs. But RPC style calls that are common with AJAX callbacks in Web applications, have gotten a lot less focus and there are a few scenarios that are not that obvious, especially if you're expecting Web API to provide functionality similar to ASP.NET AJAX style AJAX callbacks. RPC vs. 'Proper' REST RPC style HTTP calls mimic calling a method with parameters and returning a result. Rather than mapping explicit server side resources or 'nouns' RPC calls tend simply map a server side operation, passing in parameters and receiving a typed result where parameters and result values are marshaled over HTTP. Typically RPC calls - like SOAP calls - tend to always be POST operations rather than following HTTP conventions and using the GET/POST/PUT/DELETE etc. verbs to implicitly determine what operation needs to be fired. RPC might not be considered 'cool' anymore, but for typical private AJAX backend operations of a Web site I'd wager that a large percentage of use cases of Web API will fall towards RPC style calls rather than 'proper' REST style APIs. Web applications that have needs for things like live validation against data, filling data based on user inputs, handling small UI updates often don't lend themselves very well to limited HTTP verb usage. It might not be what the cool kids do, but I don't see RPC calls getting replaced by proper REST APIs any time soon. Proper REST has its place - for 'real' API scenarios that manage and publish/share resources, but for more transactional operations RPC seems a better choice and much easier to implement than trying to shoehorn a boatload of endpoint methods into a few HTTP verbs. In any case Web API does a good job of providing both RPC abstraction as well as the HTTP Verb/REST abstraction. RPC works well out of the box, but there are some differences especially if you're coming from ASP.NET AJAX service or WCF Rest when it comes to multiple parameters. Action Routing for RPC Style Calls If you've looked at Web API demos you've probably seen a bunch of examples of how to create HTTP Verb based routing endpoints. Verb based routing essentially maps a controller and then uses HTTP verbs to map the methods that are called in response to HTTP requests. This works great for resource APIs but doesn't work so well when you have many operational methods in a single controller. HTTP Verb routing is limited to the few HTTP verbs available (plus separate method signatures) and - worse than that - you can't easily extend the controller with custom routes or action routing beyond that. Thankfully Web API also supports Action based routing which allows you create RPC style endpoints fairly easily:RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumApi", action = "GetAblums" } ); This uses traditional MVC style {action} method routing which is different from the HTTP verb based routing you might have read a bunch about in conjunction with Web API. Action based routing like above lets you specify an end point method in a Web API controller either via the {action} parameter in the route string or via a default value for custom routes. Using routing you can pass multiple parameters either on the route itself or pass parameters on the query string, via ModelBinding or content value binding. For most common scenarios this actually works very well. As long as you are passing either a single complex type via a POST operation, or multiple simple types via query string or POST buffer, there's no issue. But if you need to pass multiple parameters as was easily done with WCF REST or ASP.NET AJAX things are not so obvious. Web API has no issue allowing for single parameter like this:[HttpPost] public string PostAlbum(Album album) { return String.Format("{0} {1:d}", album.AlbumName, album.Entered); } There are actually two ways to call this endpoint: albums/PostAlbum Using the Model Binder with plain POST values In this mechanism you're sending plain urlencoded POST values to the server which the ModelBinder then maps the parameter. Each property value is matched to each matching POST value. This works similar to the way that MVC's ModelBinder works. Here's how you can POST using the ModelBinder and jQuery:$.ajax( { url: "albums/PostAlbum", type: "POST", data: { AlbumName: "Dirty Deeds", Entered: "5/1/2012" }, success: function (result) { alert(result); }, error: function (xhr, status, p3, p4) { var err = "Error " + " " + status + " " + p3; if (xhr.responseText && xhr.responseText[0] == "{") err = JSON.parse(xhr.responseText).message; alert(err); } }); Here's what the POST data looks like for this request: The model binder and it's straight form based POST mechanism is great for posting data directly from HTML pages to model objects. It avoids having to do manual conversions for many operations and is a great boon for AJAX callback requests. Using Web API JSON Formatter The other option is to post data using a JSON string. The process for this is similar except that you create a JavaScript object and serialize it to JSON first.album = { AlbumName: "PowerAge", Entered: new Date(1977,0,1) } $.ajax( { url: "albums/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify(album), success: function (result) { alert(result); } }); Here the data is sent using a JSON object rather than form data and the data is JSON encoded over the wire. The trace reveals that the data is sent using plain JSON (Source above), which is a little more efficient since there's no UrlEncoding that occurs. BTW, notice that WebAPI automatically deals with the date. I provided the date as a plain string, rather than a JavaScript date value and the Formatter and ModelBinder both automatically map the date propertly to the Entered DateTime property of the Album object. Passing multiple Parameters to a Web API Controller Single parameters work fine in either of these RPC scenarios and that's to be expected. ModelBinding always works against a single object because it maps a model. But what happens when you want to pass multiple parameters? Consider an API Controller method that has a signature like the following:[HttpPost] public string PostAlbum(Album album, string userToken) Here I'm asking to pass two objects to an RPC method. Is that possible? This used to be fairly straight forward either with WCF REST and ASP.NET AJAX ASMX services, but as far as I can tell this is not directly possible using a POST operation with WebAPI. There a few workarounds that you can use to make this work: Use both POST *and* QueryString Parameters in Conjunction If you have both complex and simple parameters, you can pass simple parameters on the query string. The above would actually work with: /album/PostAlbum?userToken=sekkritt but that's not always possible. In this example it might not be a good idea to pass a user token on the query string though. It also won't work if you need to pass multiple complex objects, since query string values do not support complex type mapping. They only work with simple types. Use a single Object that wraps the two Parameters If you go by service based architecture guidelines every service method should always pass and return a single value only. The input should wrap potentially multiple input parameters and the output should convey status as well as provide the result value. You typically have a xxxRequest and a xxxResponse class that wraps the inputs and outputs. Here's what this method might look like:public PostAlbumResponse PostAlbum(PostAlbumRequest request) { var album = request.Album; var userToken = request.UserToken; return new PostAlbumResponse() { IsSuccess = true, Result = String.Format("{0} {1:d} {2}", album.AlbumName, album.Entered,userToken) }; } with these support types:public class PostAlbumRequest { public Album Album { get; set; } public User User { get; set; } public string UserToken { get; set; } } public class PostAlbumResponse { public string Result { get; set; } public bool IsSuccess { get; set; } public string ErrorMessage { get; set; } } To call this method you now have to assemble these objects on the client and send it up as JSON:var album = { AlbumName: "PowerAge", Entered: "1/1/1977" } var user = { Name: "Rick" } var userToken = "sekkritt"; $.ajax( { url: "samples/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify({ Album: album, User: user, UserToken: userToken }), success: function (result) { alert(result.Result); } }); I assemble the individual types first and then combine them in the data: property of the $.ajax() call into the actual object passed to the server, that mimics the structure of PostAlbumRequest server class that has Album, User and UserToken properties. This works well enough but it gets tedious if you have to create Request and Response types for each method signature. If you have common parameters that are always passed (like you always pass an album or usertoken) you might be able to abstract this to use a single object that gets reused for all methods, but this gets confusing too: Overload a single 'parameter' too much and it becomes a nightmare to decipher what your method actual can use. Use JObject to parse multiple Property Values out of an Object If you recall, ASP.NET AJAX and WCF REST used a 'wrapper' object to make default AJAX calls. Rather than directly calling a service you always passed an object which contained properties for each parameter: { parm1: Value, parm2: Value2 } WCF REST/ASP.NET AJAX would then parse this top level property values and map them to the parameters of the endpoint method. This automatic type wrapping functionality is no longer available directly in Web API, but since Web API now uses JSON.NET for it's JSON serializer you can actually simulate that behavior with a little extra code. You can use the JObject class to receive a dynamic JSON result and then using the dynamic cast of JObject to walk through the child objects and even parse them into strongly typed objects. Here's how to do this on the API Controller end:[HttpPost] public string PostAlbum(JObject jsonData) { dynamic json = jsonData; JObject jalbum = json.Album; JObject juser = json.User; string token = json.UserToken; var album = jalbum.ToObject<Album>(); var user = juser.ToObject<User>(); return String.Format("{0} {1} {2}", album.AlbumName, user.Name, token); } This is clearly not as nice as having the parameters passed directly, but it works to allow you to pass multiple parameters and access them using Web API. JObject is JSON.NET's generic object container which sports a nice dynamic interface that allows you to walk through the object's properties using standard 'dot' object syntax. All you have to do is cast the object to dynamic to get access to the property interface of the JSON type. Additionally JObject also allows you to parse JObject instances into strongly typed objects, which enables us here to retrieve the two objects passed as parameters from this jquery code:var album = { AlbumName: "PowerAge", Entered: "1/1/1977" } var user = { Name: "Rick" } var userToken = "sekkritt"; $.ajax( { url: "samples/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify({ Album: album, User: user, UserToken: userToken }), success: function (result) { alert(result); } }); Summary ASP.NET Web API brings many new features and many advantages over the older Microsoft AJAX and REST APIs, but realize that some things like passing multiple strongly typed object parameters will work a bit differently. It's not insurmountable, but just knowing what options are available to simulate this behavior is good to know. Now let me say here that it's probably not a good practice to pass a bunch of parameters to an API call. Ideally APIs should be closely factored to accept single parameters or a single content parameter at least along with some identifier parameters that can be passed on the querystring. But saying that doesn't mean that occasionally you don't run into a situation where you have the need to pass several objects to the server and all three of the options I mentioned might have merit in different situations. For now I'm sure the question of how to pass multiple parameters will come up quite a bit from people migrating WCF REST or ASP.NET AJAX code to Web API. At least there are options available to make it work.© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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Announcing Entity Framework Code-First (CTP5 release)

- by ScottGu

This week the data team released the CTP5 build of the new Entity Framework Code-First library. EF Code-First enables a pretty sweet code-centric development workflow for working with data. It enables you to: Develop without ever having to open a designer or define an XML mapping file Define model objects by simply writing “plain old classes” with no base classes required Use a “convention over configuration” approach that enables database persistence without explicitly configuring anything Optionally override the convention-based persistence and use a fluent code API to fully customize the persistence mapping I’m a big fan of the EF Code-First approach, and wrote several blog posts about it this summer: Code-First Development with Entity Framework 4 (July 16th) EF Code-First: Custom Database Schema Mapping (July 23rd) Using EF Code-First with an Existing Database (August 3rd) Today’s new CTP5 release delivers several nice improvements over the CTP4 build, and will be the last preview build of Code First before the final release of it. We will ship the final EF Code First release in the first quarter of next year (Q1 of 2011). It works with all .NET application types (including both ASP.NET Web Forms and ASP.NET MVC projects). Installing EF Code First You can install and use EF Code First CTP5 using one of two ways: Approach 1) By downloading and running a setup program. Once installed you can reference the EntityFramework.dll assembly it provides within your projects. or: Approach 2) By using the NuGet Package Manager within Visual Studio to download and install EF Code First within a project. To do this, simply bring up the NuGet Package Manager Console within Visual Studio (View->Other Windows->Package Manager Console) and type “Install-Package EFCodeFirst”: Typing “Install-Package EFCodeFirst” within the Package Manager Console will cause NuGet to download the EF Code First package, and add it to your current project: Doing this will automatically add a reference to the EntityFramework.dll assembly to your project: NuGet enables you to have EF Code First setup and ready to use within seconds. When the final release of EF Code First ships you’ll also be able to just type “Update-Package EFCodeFirst” to update your existing projects to use the final release. EF Code First Assembly and Namespace The CTP5 release of EF Code First has an updated assembly name, and new .NET namespace: Assembly Name: EntityFramework.dll Namespace: System.Data.Entity These names match what we plan to use for the final release of the library. Nice New CTP5 Improvements The new CTP5 release of EF Code First contains a bunch of nice improvements and refinements. Some of the highlights include: Better support for Existing Databases Built-in Model-Level Validation and DataAnnotation Support Fluent API Improvements Pluggable Conventions Support New Change Tracking API Improved Concurrency Conflict Resolution Raw SQL Query/Command Support The rest of this blog post contains some more details about a few of the above changes. Better Support for Existing Databases EF Code First makes it really easy to create model layers that work against existing databases. CTP5 includes some refinements that further streamline the developer workflow for this scenario. Below are the steps to use EF Code First to create a model layer for the Northwind sample database: Step 1: Create Model Classes and a DbContext class Below is all of the code necessary to implement a simple model layer using EF Code First that goes against the Northwind database: EF Code First enables you to use “POCO” – Plain Old CLR Objects – to represent entities within a database. This means that you do not need to derive model classes from a base class, nor implement any interfaces or data persistence attributes on them. This enables the model classes to be kept clean, easily testable, and “persistence ignorant”. The Product and Category classes above are examples of POCO model classes. EF Code First enables you to easily connect your POCO model classes to a database by creating a “DbContext” class that exposes public properties that map to the tables within a database. The Northwind class above illustrates how this can be done. It is mapping our Product and Category classes to the “Products” and “Categories” tables within the database. The properties within the Product and Category classes in turn map to the columns within the Products and Categories tables – and each instance of a Product/Category object maps to a row within the tables. The above code is all of the code required to create our model and data access layer! Previous CTPs of EF Code First required an additional step to work against existing databases (a call to Database.Initializer<Northwind>(null) to tell EF Code First to not create the database) – this step is no longer required with the CTP5 release. Step 2: Configure the Database Connection String We’ve written all of the code we need to write to define our model layer. Our last step before we use it will be to setup a connection-string that connects it with our database. To do this we’ll add a “Northwind” connection-string to our web.config file (or App.Config for client apps) like so: <connectionStrings> <add name="Northwind" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\northwind.mdf;User Instance=true" providerName="System.Data.SqlClient" /> </connectionStrings> EF “code first” uses a convention where DbContext classes by default look for a connection-string that has the same name as the context class. Because our DbContext class is called “Northwind” it by default looks for a “Northwind” connection-string to use. Above our Northwind connection-string is configured to use a local SQL Express database (stored within the \App_Data directory of our project). You can alternatively point it at a remote SQL Server. Step 3: Using our Northwind Model Layer We can now easily query and update our database using the strongly-typed model layer we just built with EF Code First. The code example below demonstrates how to use LINQ to query for products within a specific product category. This query returns back a sequence of strongly-typed Product objects that match the search criteria: The code example below demonstrates how we can retrieve a specific Product object, update two of its properties, and then save the changes back to the database: EF Code First handles all of the change-tracking and data persistence work for us, and allows us to focus on our application and business logic as opposed to having to worry about data access plumbing. Built-in Model Validation EF Code First allows you to use any validation approach you want when implementing business rules with your model layer. This enables a great deal of flexibility and power. Starting with this week’s CTP5 release, EF Code First also now includes built-in support for both the DataAnnotation and IValidatorObject validation support built-into .NET 4. This enables you to easily implement validation rules on your models, and have these rules automatically be enforced by EF Code First whenever you save your model layer. It provides a very convenient “out of the box” way to enable validation within your applications. Applying DataAnnotations to our Northwind Model The code example below demonstrates how we could add some declarative validation rules to two of the properties of our “Product” model: We are using the [Required] and [Range] attributes above. These validation attributes live within the System.ComponentModel.DataAnnotations namespace that is built-into .NET 4, and can be used independently of EF. The error messages specified on them can either be explicitly defined (like above) – or retrieved from resource files (which makes localizing applications easy). Validation Enforcement on SaveChanges() EF Code-First (starting with CTP5) now automatically applies and enforces DataAnnotation rules when a model object is updated or saved. You do not need to write any code to enforce this – this support is now enabled by default. This new support means that the below code – which violates our above rules – will automatically throw an exception when we call the “SaveChanges()” method on our Northwind DbContext: The DbEntityValidationException that is raised when the SaveChanges() method is invoked contains a “EntityValidationErrors” property that you can use to retrieve the list of all validation errors that occurred when the model was trying to save. This enables you to easily guide the user on how to fix them. Note that EF Code-First will abort the entire transaction of changes if a validation rule is violated – ensuring that our database is always kept in a valid, consistent state. EF Code First’s validation enforcement works both for the built-in .NET DataAnnotation attributes (like Required, Range, RegularExpression, StringLength, etc), as well as for any custom validation rule you create by sub-classing the System.ComponentModel.DataAnnotations.ValidationAttribute base class. UI Validation Support A lot of our UI frameworks in .NET also provide support for DataAnnotation-based validation rules. For example, ASP.NET MVC, ASP.NET Dynamic Data, and Silverlight (via WCF RIA Services) all provide support for displaying client-side validation UI that honor the DataAnnotation rules applied to model objects. The screen-shot below demonstrates how using the default “Add-View” scaffold template within an ASP.NET MVC 3 application will cause appropriate validation error messages to be displayed if appropriate values are not provided: ASP.NET MVC 3 supports both client-side and server-side enforcement of these validation rules. The error messages displayed are automatically picked up from the declarative validation attributes – eliminating the need for you to write any custom code to display them. Keeping things DRY The “DRY Principle” stands for “Do Not Repeat Yourself”, and is a best practice that recommends that you avoid duplicating logic/configuration/code in multiple places across your application, and instead specify it only once and have it apply everywhere. EF Code First CTP5 now enables you to apply declarative DataAnnotation validations on your model classes (and specify them only once) and then have the validation logic be enforced (and corresponding error messages displayed) across all applications scenarios – including within controllers, views, client-side scripts, and for any custom code that updates and manipulates model classes. This makes it much easier to build good applications with clean code, and to build applications that can rapidly iterate and evolve. Other EF Code First Improvements New to CTP5 EF Code First CTP5 includes a bunch of other improvements as well. Below are a few short descriptions of some of them: Fluent API Improvements EF Code First allows you to override an “OnModelCreating()” method on the DbContext class to further refine/override the schema mapping rules used to map model classes to underlying database schema. CTP5 includes some refinements to the ModelBuilder class that is passed to this method which can make defining mapping rules cleaner and more concise. The ADO.NET Team blogged some samples of how to do this here. Pluggable Conventions Support EF Code First CTP5 provides new support that allows you to override the “default conventions” that EF Code First honors, and optionally replace them with your own set of conventions. New Change Tracking API EF Code First CTP5 exposes a new set of change tracking information that enables you to access Original, Current & Stored values, and State (e.g. Added, Unchanged, Modified, Deleted). This support is useful in a variety of scenarios. Improved Concurrency Conflict Resolution EF Code First CTP5 provides better exception messages that allow access to the affected object instance and the ability to resolve conflicts using current, original and database values. Raw SQL Query/Command Support EF Code First CTP5 now allows raw SQL queries and commands (including SPROCs) to be executed via the SqlQuery and SqlCommand methods exposed off of the DbContext.Database property. The results of these method calls can be materialized into object instances that can be optionally change-tracked by the DbContext. This is useful for a variety of advanced scenarios. Full Data Annotations Support EF Code First CTP5 now supports all standard DataAnnotations within .NET, and can use them both to perform validation as well as to automatically create the appropriate database schema when EF Code First is used in a database creation scenario. Summary EF Code First provides an elegant and powerful way to work with data. I really like it because it is extremely clean and supports best practices, while also enabling solutions to be implemented very, very rapidly. The code-only approach of the library means that model layers end up being flexible and easy to customize. This week’s CTP5 release further refines EF Code First and helps ensure that it will be really sweet when it ships early next year. I recommend using NuGet to install and give it a try today. I think you’ll be pleasantly surprised by how awesome it is. Hope this helps, Scott

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How to Visualize your Audit Data with BI Publisher?

- by kanichiro.nishida

Do you know how many reports on your BI Publisher server are accessed yesterday ? Or, how many users accessed to the reports yesterday, or what are the average number of the users accessed to the reports during the week vs. weekend or morning vs. afternoon ? With BI Publisher 11G, now you can audit your user’s reports access and understand the state of the reporting environment at your server, each user, or each report level. At the previous post I’ve talked about what the BI Publisher’s auditing functionality and how to enable it so that BI Publisher can start collecting such data. (How to Audit and Monitor BI Publisher Reports Access?)Now, how can you visualize such auditing data to have a better understanding and gain more insights? With Fusion Middleware Audit Framework you have an option to store the auditing data into a database instead of a log file, which is the default option. Once you enable the database storage option, that means you have your auditing data (or, user report access data) in your database tables, now no brainer, you can start visualize the data, create reports, analyze, and share with BI Publisher. So, first, let’s take a look on how to enable the database storage option for the auditing data. How to Feed the Auditing Data into Database First you need to create a database schema for Fusion Middleware Audit Framework with RCU (Repository Creation Utility). If you have already installed BI Publisher 11G you should be familiar with this RCU. It creates any database schema necessary to run any Fusion Middleware products including BI stuff. And you can use the same RCU that you used for your BI or BI Publisher installation to create this Audit schema. Create Audit Schema with RCU Here are the steps: Go to $RCU_HOME/bin and execute the ‘rcu’ command Choose Create at the starting screen and click Next. Enter your database details and click Next. Choose the option to create a new prefix, for example ‘BIP’, ‘KAN’, etc. Select 'Audit Services' from the list of schemas. Click Next and accept the tablespace creation. Click Finish to start the process. After this, there should be following three Audit related schema created in your database. <prefix>_IAU (e.g. KAN_IAU) <prefix>_IAU_APPEND (e.g. KAN_IAU_APPEND) <prefix>_IAU_VIEWER (e.g. KAN_IAU_VIEWER) Setup Datasource at WebLogic After you create a database schema for your auditing data, now you need to create a JDBC connection on your WebLogic Server so the Audit Framework can access to the database schema that was created with the RCU with the previous step. Connect to the Oracle WebLogic Server administration console: http://hostname:port/console (e.g. http://report.oracle.com:7001/console) Under Services, click the Data Sources link. Click ‘Lock & Edit’ so that you can make changes Click New –> ‘Generic Datasource’ to create a new data source. Enter the following details for the new data source: Name: Enter a name such as Audit Data Source-0. JNDI Name: jdbc/AuditDB Database Type: Oracle Click Next and select ‘Oracle's Driver (Thin XA) Versions: 9.0.1 or later’ as Database Driver (if you’re using Oracle database), and click Next. The Connection Properties page appears. Enter the following information: Database Name: Enter the name of the database (SID) to which you will connect. Host Name: Enter the hostname of the database. Port: Enter the database port. Database User Name: This is the name of the audit schema that you created in RCU. The suffix is always IAU for the audit schema. For example, if you gave the prefix as ‘BIP’, then the schema name would be ‘KAN_IAU’. Password: This is the password for the audit schema that you created in RCU. Click Next. Accept the defaults, and click Test Configuration to verify the connection. Click Next Check listed servers where you want to make this JDBC connection available. Click ‘Finish’ ! After that, make sure you click ‘Activate Changes’ at the left hand side top to take the new JDBC connection in effect. Register your Audit Data Storing Database to your Domain Finally, you can register the JNDI/JDBC datasource as your Auditing data storage with Fusion Middleware Control (EM). Here are the steps: 1. Login to Fusion Middleware Control 2. Navigate to Weblogic Domain, right click on ‘bifoundation…..’, select Security, then Audit Store. 3. Click the searchlight icon next to the Datasource JNDI Name field. 4.Select the Audit JNDI/JDBC datasource you created in the previous step in the pop-up window and click OK. 5. Click Apply to continue. 6. Restart the whole WebLogic Servers in the domain. After this, now the BI Publisher should start feeding all the auditing data into the database table called ‘IAU_BASE’. Try login to BI Publisher and open a couple of reports, you should see the activity audited in the ‘IAU_BASE’ table. If not working, you might want to check the log file, which is located at $BI_HOME/user_projects/domains/bifoundation_domain/servers/AdminServer/logs/AdminServer-diagnostic.log to see if there is any error. Once you have the data in the database table, now, it’s time to visualize with BI Publisher reports! Create a First BI Publisher Auditing Report Register Auditing Datasource as JNDI datasource First thing you need to do is to register the audit datasource (JNDI/JDBC connection) you created in the previous step as JNDI data source at BI Publisher. It is a JDBC connection registered as JNDI, that means you don’t need to create a new JDBC connection by typing the connection URL, username/password, etc. You can just register it using the JNDI name. (e.g. jdbc/AuditDB) Login to BI Publisher as Administrator (e.g. weblogic) Go to Administration Page Click ‘JNDI Connection’ under Data Sources and Click ‘New’ Type Data Source Name and JNDI Name. The JNDI Name is the one you created in the WebLogic Console as the auditing datasource. (e.g. jdbc/AuditDB) Click ‘Test Connection’ to make sure the datasource connection works. Provide appropriate roles so that the report developers or viewers can share this data source to view reports. Click ‘Apply’ to save. Create Data Model Select Data Model from the tool bar menu ‘New’ Set ‘Default Data Source’ to the audit JNDI data source you have created in the previous step. Select ‘SQL Query’ for your data set Use Query Builder to build a query or just type a sql query. Either way, the table you want to report against is ‘IAU_BASE’. This IAU_BASE table contains all the auditing data for other products running on the WebLogic Server such as JPS, OID, etc. So, if you care only specific to BI Publisher then you want to filter by using ‘IAU_COMPONENTTYPE’ column which contains the product name (e.g. ’xmlpserver’ for BI Publisher). Here is my sample sql query. select "IAU_BASE"."IAU_COMPONENTTYPE" as "IAU_COMPONENTTYPE", "IAU_BASE"."IAU_EVENTTYPE" as "IAU_EVENTTYPE", "IAU_BASE"."IAU_EVENTCATEGORY" as "IAU_EVENTCATEGORY", "IAU_BASE"."IAU_TSTZORIGINATING" as "IAU_TSTZORIGINATING", to_char("IAU_TSTZORIGINATING", 'YYYY-MM-DD') IAU_DATE, to_char("IAU_TSTZORIGINATING", 'DAY') as IAU_DAY, to_char("IAU_TSTZORIGINATING", 'HH24') as IAU_HH24, to_char("IAU_TSTZORIGINATING", 'WW') as IAU_WEEK_OF_YEAR, "IAU_BASE"."IAU_INITIATOR" as "IAU_INITIATOR", "IAU_BASE"."IAU_RESOURCE" as "IAU_RESOURCE", "IAU_BASE"."IAU_TARGET" as "IAU_TARGET", "IAU_BASE"."IAU_MESSAGETEXT" as "IAU_MESSAGETEXT", "IAU_BASE"."IAU_FAILURECODE" as "IAU_FAILURECODE", "IAU_BASE"."IAU_REMOTEIP" as "IAU_REMOTEIP" from "KAN3_IAU"."IAU_BASE" "IAU_BASE" where "IAU_BASE"."IAU_COMPONENTTYPE" = 'xmlpserver' Once you saved a sample XML for this data model, now you can create a report with this data model. Create Report Now you can use one of the BI Publisher’s layout options to design the report layout and visualize the auditing data. I’m a big fan of Online Layout Editor, it’s just so easy and simple to create reports, and on top of that, all the reports created with Online Layout Editor has the Interactive View with automatic data linking and filtering feature without any setting or coding. If you haven’t checked the Interactive View or Online Layout Editor you might want to check these previous blog posts. (Interactive Reporting with BI Publisher 11G, Interactive Master Detail Report Just A Few Clicks Away!) But of course, you can use other layout design option such as RTF template. Here are some sample screenshots of my report design with Online Layout Editor. Visualize and Gain More Insights about your Customers (Users) ! Now you can visualize your auditing data to have better understanding and gain more insights about your reporting environment you manage. It’s been actually helping me personally to answer the questios like below. How many reports are accessed or opened yesterday, today, last week ? Who is accessing which report at what time ? What are the time windows when the most of the reports access happening ? What are the most viewed reports ? Who are the active users ? What are the # of reports access or user access trend for the last month, last 6 months, last 12 months, etc ? I was talking with one of the best concierge in the world at this hotel the other day, and he was telling me that the best concierge knows about their customers inside-out therefore they can provide a very private service that is customized to each customer to meet each customer’s specific needs. Well, this is true when it comes to how to administrate and manage your reporting environment, right ? The best way to serve your customers (report users, including both viewers and developers) is to understand how they use, what they use, when they use. Auditing is not just about compliance, but it’s the way to improve the customer service. The BI Publisher 11G Auditing feature enables just that to help you understand your customers better. Happy customer service, be the best reporting concierge! p.s. please share with us on what other information would be helpful for you for the auditing! Always, any feedback is a great value and inspiration for us!

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nikto probe warning messages

- by julio

Hi-- I have a pretty standard VPS running Ubuntu 8.1, Apache 2.2, PHP 5 etc. -- standard Lamp stack. I am using suhosin and have tried my best to plug the obvious stuff, since I'm the only user-- there's no SSH access except via pubkey on a non-standard port, there's no root access by SSH, no FTP server running, iptables is set to discard anything outside of basically port 80 or my SSH port (there's no mail server or anything else). However, I've still been compromised (not badly as far as I can tell) probably by a SQL injection. I've locked down the SQL user (there's only one outside of root, and he's got limited priv, no file etc.) So I ran nikto to see what I'm doing wrong, and there's a list of things I've never seen, and can't find using "find" or any other method I'm aware of. See below: + /autologon.html?10514: Remotely Anywhere 5.10.415 is vulnerable to XSS attacks that can lead to cookie theft or privilege escalation. This is typically found on port 2000. + /servlet/webacc?User.html=noexist: Netware web access may reveal full path of the web server. Apply vendor patch or upgrade. + OSVDB-35878: /modules.php?name=Members_List&letter='%20OR%20pass%20LIKE%20'a%25'/*: PHP Nuke module allows user names and passwords to be viewed. + OSVDB-3092: /sitemap.xml: This gives a nice listing of the site content. + OSVDB-12184: /index.php?=PHPB8B5F2A0-3C92-11d3-A3A9-4C7B08C10000: PHP reveals potentially sensitive information via certain HTTP requests which contain specific QUERY strings. + OSVDB-12184: /some.php?=PHPE9568F36-D428-11d2-A769-00AA001ACF42: PHP reveals potentially sensitive information via certain HTTP requests which contain specific QUERY strings. + OSVDB-12184: /some.php?=PHPE9568F34-D428-11d2-A769-00AA001ACF42: PHP reveals potentially sensitive information via certain HTTP requests which contain specific QUERY strings. + OSVDB-12184: /some.php?=PHPE9568F35-D428-11d2-A769-00AA001ACF42: PHP reveals potentially sensitive information via certain HTTP requests which contain specific QUERY strings. + OSVDB-3092: /administrator/: This might be interesting... + OSVDB-3092: /Agent/: This might be interesting... + OSVDB-3092: /includes/: This might be interesting... + OSVDB-3092: /logs/: This might be interesting... + OSVDB-3092: /tmp/: This might be interesting... + ERROR: /servlet/Counter returned an error: error reading HTTP response + OSVDB-3268: /icons/: Directory indexing is enabled: /icons + OSVDB-3268: /images/: Directory indexing is enabled: /images + OSVDB-3299: /forumscalendar.php?calbirthdays=1&action=getday&day=2001-8-15&comma=%22;echo%20'';%20echo%20%60id%20%60;die();echo%22: Vbulletin allows remote command execution. See link + OSVDB-3299: /forumzcalendar.php?calbirthdays=1&action=getday&day=2001-8-15&comma=%22;echo%20'';%20echo%20%60id%20%60;die();echo%22: Vbulletin allows remote command execution. See link + OSVDB-3299: /htforumcalendar.php?calbirthdays=1&action=getday&day=2001-8-15&comma=%22;echo%20'';%20echo%20%60id%20%60;die();echo%22: Vbulletin allows remote command execution. See link + OSVDB-3299: /vbcalendar.php?calbirthdays=1&action=getday&day=2001-8-15&comma=%22;echo%20'';%20echo%20%60id%20%60;die();echo%22: Vbulletin allows remote command execution. See link + OSVDB-3299: /vbulletincalendar.php?calbirthdays=1&action=getday&day=2001-8-15&comma=%22;echo%20'';%20echo%20%60id%20%60;die();echo%22: Vbulletin allows remote command execution. See link + OSVDB-6659: /kCKAowoWuZkKCUPH7Mr675ILd9hFg1lnyc1tWUuEbkYkFCpCdEnCKkkd9L0bY34tIf9l6t2owkUp9nI5PIDmQzMokDbp71QFTZGxdnZhTUIzxVrQhVgwmPYsMK7g34DURzeiy3nyd4ezX5NtUozTGqMkxDrLheQmx4dDYlRx0vKaX41JX40GEMf21TKWxHAZSUxjgXUnIlKav58GZQ5LNAwSAn13l0w<font%20size=50>DEFACED<!--//--: MyWebServer 1.0.2 is vulnerable to HTML injection. Upgrade to a later version. I understand about the trace and index, but what about the vbulletin and autologin? I've searched, and I can't find any files like that on the server. I have no idea about the "MyWebServer" stuff, the PHP Nuke, or the Netware/servlet stuff-- there's nothing really on the server except a pretty standard Joomla site (updated to the latest version). Any help with these messages and/or what I'm doing wrong is very much appreciated.

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ASPNET WebAPI REST Guidance

- by JoshReuben

ASP.NET Web API is an ideal platform for building RESTful applications on the .NET Framework. While I may be more partial to NodeJS these days, there is no denying that WebAPI is a well engineered framework. What follows is my investigation of how to leverage WebAPI to construct a RESTful frontend API. The Advantages of REST Methodology over SOAP Simpler API for CRUD ops Standardize Development methodology - consistent and intuitive Standards based à client interop Wide industry adoption, Ease of use à easy to add new devs Avoid service method signature blowout Smaller payloads than SOAP Stateless à no session data means multi-tenant scalability Cache-ability Testability General RESTful API Design Overview · utilize HTTP Protocol - Usage of HTTP methods for CRUD, standard HTTP response codes, common HTTP headers and Mime Types · Resources are mapped to URLs, actions are mapped to verbs and the rest goes in the headers. · keep the API semantic, resource-centric – A RESTful, resource-oriented service exposes a URI for every piece of data the client might want to operate on. A REST-RPC Hybrid exposes a URI for every operation the client might perform: one URI to fetch a piece of data, a different URI to delete that same data. utilize Uri to specify CRUD op, version, language, output format: http://api.MyApp.com/{ver}/{lang}/{resource_type}/{resource_id}.{output_format}?{key&filters} · entity CRUD operations are matched to HTTP methods: · Create - POST / PUT · Read – GET - cacheable · Update – PUT · Delete - DELETE · Use Uris to represent a hierarchies - Resources in RESTful URLs are often chained · Statelessness allows for idempotency – apply an op multiple times without changing the result. POST is non-idempotent, the rest are idempotent (if DELETE flags records instead of deleting them). · Cache indication - Leverage HTTP headers to label cacheable content and indicate the permitted duration of cache · PUT vs POST - The client uses PUT when it determines which URI (Id key) the new resource should have. The client uses POST when the server determines they key. PUT takes a second param – the id. POST creates a new resource. The server assigns the URI for the new object and returns this URI as part of the response message. Note: The PUT method replaces the entire entity. That is, the client is expected to send a complete representation of the updated product. If you want to support partial updates, the PATCH method is preferred DELETE deletes a resource at a specified URI – typically takes an id param · Leverage Common HTTP Response Codes in response headers 200 OK: Success 201 Created - Used on POST request when creating a new resource. 304 Not Modified: no new data to return. 400 Bad Request: Invalid Request. 401 Unauthorized: Authentication. 403 Forbidden: Authorization 404 Not Found – entity does not exist. 406 Not Acceptable – bad params. 409 Conflict - For POST / PUT requests if the resource already exists. 500 Internal Server Error 503 Service Unavailable · Leverage uncommon HTTP Verbs to reduce payload sizes HEAD - retrieves just the resource meta-information. OPTIONS returns the actions supported for the specified resource. PATCH - partial modification of a resource. · When using PUT, POST or PATCH, send the data as a document in the body of the request. Don't use query parameters to alter state. · Utilize Headers for content negotiation, caching, authorization, throttling o Content Negotiation – choose representation (e.g. JSON or XML and version), language & compression. Signal via RequestHeader.Accept & ResponseHeader.Content-Type Accept: application/json;version=1.0 Accept-Language: en-US Accept-Charset: UTF-8 Accept-Encoding: gzip o Caching - ResponseHeader: Expires (absolute expiry time) or Cache-Control (relative expiry time) o Authorization - basic HTTP authentication uses the RequestHeader.Authorization to specify a base64 encoded string "username:password". can be used in combination with SSL/TLS (HTTPS) and leverage OAuth2 3rd party token-claims authorization. Authorization: Basic sQJlaTp5ZWFslylnaNZ= o Rate Limiting - Not currently part of HTTP so specify non-standard headers prefixed with X- in the ResponseHeader. X-RateLimit-Limit: 10000 X-RateLimit-Remaining: 9990 · HATEOAS Methodology - Hypermedia As The Engine Of Application State – leverage API as a state machine where resources are states and the transitions between states are links between resources and are included in their representation (hypermedia) – get API metadata signatures from the response Link header - in a truly REST based architecture any URL, except the initial URL, can be changed, even to other servers, without worrying about the client. · error responses - Do not just send back a 200 OK with every response. Response should consist of HTTP error status code (JQuery has automated support for this), A human readable message , A Link to a meaningful state transition , & the original data payload that was problematic. · the URIs will typically map to a server-side controller and a method name specified by the type of request method. Stuff all your calls into just four methods is not as crazy as it sounds. · Scoping - Path variables look like you’re traversing a hierarchy, and query variables look like you’re passing arguments into an algorithm · Mapping URIs to Controllers - have one controller for each resource is not a rule – can consolidate - route requests to the appropriate controller and action method · Keep URls Consistent - Sometimes it’s tempting to just shorten our URIs. not recommend this as this can cause confusion · Join Naming – for m-m entity relations there may be multiple hierarchy traversal paths · Routing – useful level of indirection for versioning, server backend mocking in development ASPNET WebAPI Considerations ASPNET WebAPI implements a lot (but not all) RESTful API design considerations as part of its infrastructure and via its coding convention. Overview When developing an API there are basically three main steps: 1. Plan out your URIs 2. Setup return values and response codes for your URIs 3. Implement a framework for your API. Design · Leverage Models MVC folder · Repositories – support IoC for tests, abstraction · Create DTO classes – a level of indirection decouples & allows swap out · Self links can be generated using the UrlHelper · Use IQueryable to support projections across the wire · Models can support restful navigation properties – ICollection<T> · async mechanism for long running ops - return a response with a ticket – the client can then poll or be pushed the final result later. · Design for testability - Test using HttpClient , JQuery ( $.getJSON , $.each) , fiddler, browser debug. Leverage IDependencyResolver – IoC wrapper for mocking · Easy debugging - IE F12 developer tools: Network tab, Request Headers tab Routing · HTTP request method is matched to the method name. (This rule applies only to GET, POST, PUT, and DELETE requests.) · {id}, if present, is matched to a method parameter named id. · Query parameters are matched to parameter names when possible · Done in config via Routes.MapHttpRoute – similar to MVC routing · Can alternatively: o decorate controller action methods with HttpDelete, HttpGet, HttpHead,HttpOptions, HttpPatch, HttpPost, or HttpPut., + the ActionAttribute o use AcceptVerbsAttribute to support other HTTP verbs: e.g. PATCH, HEAD o use NonActionAttribute to prevent a method from getting invoked as an action · route table Uris can support placeholders (via curly braces{}) – these can support default values and constraints, and optional values · The framework selects the first route in the route table that matches the URI. Response customization · Response code: By default, the Web API framework sets the response status code to 200 (OK). But according to the HTTP/1.1 protocol, when a POST request results in the creation of a resource, the server should reply with status 201 (Created). Non Get methods should return HttpResponseMessage · Location: When the server creates a resource, it should include the URI of the new resource in the Location header of the response. public HttpResponseMessage PostProduct(Product item) { item = repository.Add(item); var response = Request.CreateResponse<Product>(HttpStatusCode.Created, item); string uri = Url.Link("DefaultApi", new { id = item.Id }); response.Headers.Location = new Uri(uri); return response; } Validation · Decorate Models / DTOs with System.ComponentModel.DataAnnotations properties RequiredAttribute, RangeAttribute. · Check payloads using ModelState.IsValid · Under posting – leave out values in JSON payload à JSON formatter assigns a default value. Use with RequiredAttribute · Over-posting - if model has RO properties à use DTO instead of model · Can hook into pipeline by deriving from ActionFilterAttribute & overriding OnActionExecuting Config · Done in App_Start folder > WebApiConfig.cs – static Register method: HttpConfiguration param: The HttpConfiguration object contains the following members. Member Description DependencyResolver Enables dependency injection for controllers. Filters Action filters – e.g. exception filters. Formatters Media-type formatters. by default contains JsonFormatter, XmlFormatter IncludeErrorDetailPolicy Specifies whether the server should include error details, such as exception messages and stack traces, in HTTP response messages. Initializer A function that performs final initialization of the HttpConfiguration. MessageHandlers HTTP message handlers - plug into pipeline ParameterBindingRules A collection of rules for binding parameters on controller actions. Properties A generic property bag. Routes The collection of routes. Services The collection of services. · Configure JsonFormatter for circular references to support links: PreserveReferencesHandling.Objects Documentation generation · create a help page for a web API, by using the ApiExplorer class. · The ApiExplorer class provides descriptive information about the APIs exposed by a web API as an ApiDescription collection · create the help page as an MVC view public ILookup<string, ApiDescription> GetApis() { return _explorer.ApiDescriptions.ToLookup( api => api.ActionDescriptor.ControllerDescriptor.ControllerName); · provide documentation for your APIs by implementing the IDocumentationProvider interface. Documentation strings can come from any source that you like – e.g. extract XML comments or define custom attributes to apply to the controller [ApiDoc("Gets a product by ID.")] [ApiParameterDoc("id", "The ID of the product.")] public HttpResponseMessage Get(int id) · GlobalConfiguration.Configuration.Services – add the documentation Provider · To hide an API from the ApiExplorer, add the ApiExplorerSettingsAttribute Plugging into the Message Handler pipeline · Plug into request / response pipeline – derive from DelegatingHandler and override theSendAsync method – e.g. for logging error codes, adding a custom response header · Can be applied globally or to a specific route Exception Handling · Throw HttpResponseException on method failures – specify HttpStatusCode enum value – examine this enum, as its values map well to typical op problems · Exception filters – derive from ExceptionFilterAttribute & override OnException. Apply on Controller or action methods, or add to global HttpConfiguration.Filters collection · HttpError object provides a consistent way to return error information in the HttpResponseException response body. · For model validation, you can pass the model state to CreateErrorResponse, to include the validation errors in the response public HttpResponseMessage PostProduct(Product item) { if (!ModelState.IsValid) { return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState); Cookie Management · Cookie header in request and Set-Cookie headers in a response - Collection of CookieState objects · Specify Expiry, max-age resp.Headers.AddCookies(new CookieHeaderValue[] { cookie }); Internet Media Types, formatters and serialization · Defaults to application/json · Request Accept header and response Content-Type header · determines how Web API serializes and deserializes the HTTP message body. There is built-in support for XML, JSON, and form-urlencoded data · customizable formatters can be inserted into the pipeline · POCO serialization is opt out via JsonIgnoreAttribute, or use DataMemberAttribute for optin · JSON serializer leverages NewtonSoft Json.NET · loosely structured JSON objects are serialzed as JObject which derives from Dynamic · to handle circular references in json: json.SerializerSettings.PreserveReferencesHandling = PreserveReferencesHandling.All à {"$ref":"1"}. · To preserve object references in XML [DataContract(IsReference=true)] · Content negotiation Accept: Which media types are acceptable for the response, such as “application/json,” “application/xml,” or a custom media type such as "application/vnd.example+xml" Accept-Charset: Which character sets are acceptable, such as UTF-8 or ISO 8859-1. Accept-Encoding: Which content encodings are acceptable, such as gzip. Accept-Language: The preferred natural language, such as “en-us”. o Web API uses the Accept and Accept-Charset headers. (At this time, there is no built-in support for Accept-Encoding or Accept-Language.) · Controller methods can take JSON representations of DTOs as params – auto-deserialization · Typical JQuery GET request: function find() { var id = $('#prodId').val(); $.getJSON("api/products/" + id, function (data) { var str = data.Name + ': $' + data.Price; $('#product').text(str); }) .fail( function (jqXHR, textStatus, err) { $('#product').text('Error: ' + err); }); } · Typical GET response: HTTP/1.1 200 OK Server: ASP.NET Development Server/10.0.0.0 Date: Mon, 18 Jun 2012 04:30:33 GMT X-AspNet-Version: 4.0.30319 Cache-Control: no-cache Pragma: no-cache Expires: -1 Content-Type: application/json; charset=utf-8 Content-Length: 175 Connection: Close [{"Id":1,"Name":"TomatoSoup","Price":1.39,"ActualCost":0.99},{"Id":2,"Name":"Hammer", "Price":16.99,"ActualCost":10.00},{"Id":3,"Name":"Yo yo","Price":6.99,"ActualCost": 2.05}] True OData support · Leverage Query Options $filter, $orderby, $top and $skip to shape the results of controller actions annotated with the [Queryable]attribute. [Queryable] public IQueryable<Supplier> GetSuppliers() · Query: ~/Suppliers?$filter=Name eq ‘Microsoft’ · Applies the following selection filter on the server: GetSuppliers().Where(s => s.Name == “Microsoft”) · Will pass the result to the formatter. · true support for the OData format is still limited - no support for creates, updates, deletes, $metadata and code generation etc · vnext: ability to configure how EditLinks, SelfLinks and Ids are generated Self Hosting no dependency on ASPNET or IIS: using (var server = new HttpSelfHostServer(config)) { server.OpenAsync().Wait(); Tracing · tracability tools, metrics – e.g. send to nagios · use your choice of tracing/logging library, whether that is ETW,NLog, log4net, or simply System.Diagnostics.Trace. · To collect traces, implement the ITraceWriter interface public class SimpleTracer : ITraceWriter { public void Trace(HttpRequestMessage request, string category, TraceLevel level, Action<TraceRecord> traceAction) { TraceRecord rec = new TraceRecord(request, category, level); traceAction(rec); WriteTrace(rec); · register the service with config · programmatically trace – has helper extension methods: Configuration.Services.GetTraceWriter().Info( · Performance tracing - pipeline writes traces at the beginning and end of an operation - TraceRecord class includes aTimeStamp property, Kind property set to TraceKind.Begin / End Security · Roles class methods: RoleExists, AddUserToRole · WebSecurity class methods: UserExists, .CreateUserAndAccount · Request.IsAuthenticated · Leverage HTTP 401 (Unauthorized) response · [AuthorizeAttribute(Roles="Administrator")] – can be applied to Controller or its action methods · See section in WebApi document on "Claim-based-security for ASP.NET Web APIs using DotNetOpenAuth" – adapt this to STS.--> Web API Host exposes secured Web APIs which can only be accessed by presenting a valid token issued by the trusted issuer. http://zamd.net/2012/05/04/claim-based-security-for-asp-net-web-apis-using-dotnetopenauth/ · Use MVC membership provider infrastructure and add a DelegatingHandler child class to the WebAPI pipeline - http://stackoverflow.com/questions/11535075/asp-net-mvc-4-web-api-authentication-with-membership-provider - this will perform the login actions · Then use AuthorizeAttribute on controllers and methods for role mapping- http://sixgun.wordpress.com/2012/02/29/asp-net-web-api-basic-authentication/ · Alternate option here is to rely on MVC App : http://forums.asp.net/t/1831767.aspx/1

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CodePlex Daily Summary for Monday, March 07, 2011

CodePlex Daily Summary for Monday, March 07, 2011Popular ReleasesDotNetAge -a lightweight Mvc jQuery CMS: DotNetAge 2: What is new in DotNetAge 2.0 ? Completely update DJME to DJME2, enhance user experience ,more beautiful and more interactively visit DJME project home to lean more about DJME http://www.dotnetage.com/sites/home/djme.html A new widget engine has came! Faster and easiler. Runtime performance enhanced. SEO enhanced. UI Designer enhanced. A new web resources explorer. Page manager enhanced. BlogML supports added that allows you import/export your blog data to/from dotnetage publishi...Master Data Services Manager: stable 1.0.3: Update 2011-03-07 : bug fixes added external configuration File : configuration.config added TreeView Display of model (still in dev) http://img96.imageshack.us/img96/5067/screenshot073l.jpg added Connection Parameters (username, domain, password, stored encrypted in configuration file) http://img402.imageshack.us/img402/5350/screenshot072qc.jpgSharePoint Content Inventory: Release 1.1: Release 1.1Menu and Context Menu for Silverlight 4.0: Silverlight Menu and Context Menu v2.4 Beta: - Moved the core of the PopupMenu class to the new PopupMenuBase class. - Renamed the MenuTriggerElement class to MenuTriggerRelationship. - Renamed the ApplicationMenus property to MenuTriggers. - Renamed the ImageLeftOpacity property to ImageOpacity. - Renamed the ImageLeftVisibility property to ImageVisibility. - Renamed the ImageLeftMinWidth property to ImageMinWidth. - Renamed the ImagePathForRightMargin property to ImageRightPath. - Renamed the ImageSourceForRightMargin property to Ima...Kooboo CMS: Kooboo CMS 3.0 Beta: Files in this downloadkooboo_CMS.zip: The kooboo application files Content_DBProvider.zip: Additional content database implementation of MSSQL,SQLCE, RavenDB and MongoDB. Default is XML based database. To use them, copy the related dlls into web root bin folder and remove old content provider dlls. Content provider has the name like "Kooboo.CMS.Content.Persistence.SQLServer.dll" View_Engines.zip: Supports of Razor, webform and NVelocity view engine. Copy the dlls into web root bin folder t...ASP.NET MVC Project Awesome, jQuery Ajax helpers (controls): 1.7.2: A rich set of helpers (controls) that you can use to build highly responsive and interactive Ajax-enabled Web applications. These helpers include Autocomplete, AjaxDropdown, Lookup, Confirm Dialog, Popup Form, Popup and Pager added fullscreen for the popup and popupformIronPython: 2.7 Release Candidate 2: On behalf of the IronPython team, I am pleased to announce IronPython 2.7 Release Candidate 2. The releases contains a few minor bug fixes, including a working webbrowser module. Please see the release notes for 61395 for what was fixed in previous releases.LINQ to Twitter: LINQ to Twitter Beta v2.0.20: Mono 2.8, Silverlight, OAuth, 100% Twitter API coverage, streaming, extensibility via Raw Queries, and added documentation.IIS Tuner: IIS Tuner 1.0: IIS and ASP.NET performance optimization toolMinemapper: Minemapper v0.1.6: Once again supports biomes, thanks to an updated Minecraft Biome Extractor, which added support for the new Minecraft beta v1.3 map format. Updated mcmap to support new biome format.CRM 2011 OData Query Designer: CRM 2011 OData Query Designer: The CRM 2011 OData Query Designer is a Silverlight 4 application that is packaged as a Managed CRM 2011 Solution. This tool allows you to build OData queries by selecting filter criteria, select attributes and order by attributes. The tool also allows you to Execute the query and view the ATOM and JSON data returned. The look and feel of this component will improve and new functionality will be added in the near future so please provide feedback on your experience. Import this solution int...Sandcastle Help File Builder: SHFB v1.9.3.0 Release: This release supports the Sandcastle June 2010 Release (v2.6.10621.1). It includes full support for generating, installing, and removing MS Help Viewer files. This new release is compiled under .NET 4.0, supports Visual Studio 2010 solutions and projects as documentation sources, and adds support for projects targeting the Silverlight Framework. This release uses the Sandcastle Guided Installation package used by Sandcastle Styles. Download and extract to a folder and then run SandcastleI...mytrip.mvc (CMS & e-Commerce): mytrip.mvc 1.0.53.0 beta 2: New SEO Optimisation WEB.mytrip.mvc 1.0.53.0 Web for install hosting System Requirements: NET 4.0, MSSQL 2008 or MySql (auto creation table to database) if .\SQLEXPRESS auto creation database (App_Data folder) SRC.mytrip.mvc 1.0.53.0 System Requirements: Visual Studio 2010 or Web Deweloper 2010 MSSQL 2008 or MySql (auto creation table to database) if .\SQLEXPRESS auto creation database (App_Data folder) Connector/Net 6.3.5, MVC3 RTM WARNING For run and debug SRC.mytrip.mvc 1.0.53.0 dow...AutoLoL: AutoLoL v1.6.4: It is now possible to run the clicker anyway when it can't detect the Masteries Window Fixed a critical bug in the open file dialog Removed the resize button Some UI changes 3D camera movement is now more intuitive (Trackball rotation) When an error occurs on the clicker it will attempt to focus AutoLoLYAF.NET (aka Yet Another Forum.NET): v1.9.5.5 RTW: YAF v1.9.5.5 RTM (Date: 3/4/2011 Rev: 4742) Official Discussion Thread here: http://forum.yetanotherforum.net/yaf_postsm47149_v1-9-5-5-RTW--Date-3-4-2011-Rev-4742.aspx Changes in v1.9.5.5 Rev. #4661 - Added "Copy" function to forum administration -- Now instead of having to manually re-enter all the access masks, etc, you can just duplicate an existing forum and modify after the fact. Rev. #4642 - New Setting to Enable/Disable Last Unread posts links Rev. #4641 - Added Arabic Language t...Snippet Designer: Snippet Designer 1.3.1: Snippet Designer 1.3.1 for Visual Studio 2010This is a bug fix release. Change logFixed bug where Snippet Designer would fail if you had the most recent Productivity Power Tools installed Fixed bug where "Export as Snippet" was failing in non-english locales Fixed bug where opening a new .snippet file would fail in non-english localesChiave File Encryption: Chiave 1.0: Final Relase for Chave 1.0 Stable: Application for file encryption and decryption using 512 Bit rijndael encyrption algorithm with simple to use UI. Its written in C# and compiled in .Net version 3.5. It incorporates features of Windows 7 like Jumplists, Taskbar progress and Aero Glass. Now with added support to Windows XP! Change Log from 0.9.2 to 1.0: ==================== Added: > Added Icon Overlay for Windows 7 Taskbar Icon. >Added Thumbnail Toolbar buttons to make the navigation easier...ASP.NET: Sprite and Image Optimization Preview 3: The ASP.NET Sprite and Image Optimization framework is designed to decrease the amount of time required to request and display a page from a web server by performing a variety of optimizations on the page’s images. This is the third preview of the feature and works with ASP.NET Web Forms 4, ASP.NET MVC 3, and ASP.NET Web Pages (Razor) projects. The binaries are also available via NuGet: AspNetSprites-Core AspNetSprites-WebFormsControl AspNetSprites-MvcAndRazorHelper It includes the foll...Network Monitor Open Source Parsers: Microsoft Network Monitor Parsers 3.4.2554: The Network Monitor Parsers packages contain parsers for more than 400 network protocols, including RFC based public protocols and protocols for Microsoft products defined in the Microsoft Open Specifications for Windows and SQL Server. NetworkMonitor_Parsers.msi is the base parser package which defines parsers for commonly used public protocols and protocols for Microsoft Windows. In this release, we have added 4 new protocol parsers and updated 79 existing parsers in the NetworkMonitor_Pa...Image Resizer for Windows: Image Resizer 3 Preview 1: Prepare to have your minds blown. This is the first preview of what will eventually become 39613. There are still a lot of rough edges and plenty of areas still under construction, but for your basic needs, it should be relativly stable. Note: You will need the .NET Framework 4 installed to use this version. Below is a status report of where this release is in terms of the overall goal for version 3. If you're feeling a bit technically ambitious and want to check out some of the features th...New ProjectsAppFactory: Die AppFactory Dient zur Vereinfachung der entwicklung von WPF Anwedungen. Es ist in C# entwickelt.Change the Default Playback Sound Device: ChangePlaybackDevice makes it easier for personal user to change the default playback sound device. You'll no longer have to change the default playback sound device by hand. It's developed in C#. Conectayas: Conectayas is an open source "Connect Four" alike game but transformable to "Tic-Tac-Toe" and to a lot of similar games that uses mouse. Written in DHTML (JavaScript, CSS and HTML). Very configurable. This cross-platform and cross-browser game was tested under BeOS, Linux, *BSD, Windows and others.Diamond: The all in one toolkit for WPF and Silverligth projects.Digital Disk File Format: Digital Disk is a File format that uses a simple key system, it is currently in development. It is written in vb.net, but will be expanded into other languagesdotnetMvcMalll: this is a asp.net mvc mallEasyCache .NET: EasyCache .NET is a simplified API over the ASP.NET Cache object. Its purpose is to offer a more concise syntax for adding and retrieving items from the cache.Eric Fang SharePoint workflow activities: Eric Fang SharePoint workflow activitiesExpert.NET: Expert.NET is an expert system framework for .NET applications. Written in F#, it provides constructs for defining probabilistic rulesets, as well as an inference engine. Expert.NET is ideal for encoding domain knowledge used by troubleshooting applications.GameGolem: The GameGolem is an XNA Casual Gamers portal. The purpose is to create a single ClickOnce deployed "Game Launcher" which exposes simple API for games to keep track of highscores, achivements, etc. GameGolem will become a Kongregate-like XNA-based casual games portal.Hundiyas: Hundiyas is an open source "Battleship" alike game totally written in DHTML (JavaScript, CSS and HTML) that uses mouse. This cross-platform and cross-browser game was tested under BeOS, Linux, *BSD, Windows and others.ISBC: Practicas ISBC 10/11maocaijun.database: databaseNCLI: A simple API for command line argument parsing, written in C#.nEMO: nEMO is a pure C# framework for Evolutionary Multiobjective Optimization.N-tier architecture sample: A sample on how to practically design a system following an n-tier (multitier) architecture in line with the patterns and practices presented by Microsofts Application Architectural Guide 2.0. Focus is on a service application and it´s client applications of various types.PostsByMonth Widget: This is a simple widget for the Graffiti CMS application that allows you to get a monthly list of new posts to the site. It's configurable to allow for the # of posts to display as well as the the format of the month/year header, the title and the individual line entries. This is written in .Net 3.5 with Vb.Net.Puzzle Pal: Smartphone assistant for all your puzzling events.RavenDB Notification: Notification plugin for RavenDB. With this plugin you are able to subscribe to insert and delete notifications from the RavenDB server. Very helpfull if you need to process new documents on the remote clients and you do not like to query DB for new changes.Teamwork by Intrigue Deviation: A feature-rich team collaboration and project management effort built around Scrum methodology with MVC/2.test_flow: test flowTicari Uygulama Paketi: Ticari Uygulama Paketi (TUP), Microsoft Ofis 2010 ürünleri için gelistirilmis eklenti yazilimidir.XpsViewer: XpsVieweryaphan: yaphan cms.

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DNS resolution problems; dig SERVFAIL error

- by JustinP

I'm setting up a couple of dedicated servers, and having problems setting up my nameservers properly. One of these is a LEMP server (LAMP with nginx in place of Apache), and the other will function solely as an email server, running exim/dovecot/ASSP antispam (no Apache). The LEMP server is CentOS 5.5, with no control panel, while the email server is CentOS 5.5 as well, with cPanel/WHM. So, I've had problems getting DNS set up properly. I have two domains, each one pointing to one of these servers. The nameservers are registered correctly with the domain registrar, and the nameserver IPs are entered correctly as well. I've spoken to tech support at the registrar and they confirm that everything is set up on their end. Not knowing much about DNS, I googled nameservers and DNS until I nearly went blind, and spent hours messing with the configuration. Eventually, I got the LEMP server's DNS working properly (no cPanel). Pleased with this triumph, I'm trying to mimic that configuration and repeat the process with the email server, and it's just not happening. The nameserver starts and stops, but the domain doesn't resolve. Things I have tried Going through standard procedures to set up DNS in WHM Clearing all DNS information, uninstalling BIND, then reinstalling all of that and again going through WHM procedures for setting up DNS Clearing all DNS information, and setting up BIND via shell (completely outside of cPanel) by using my config and zone files from the LEMP server as a template named runs just fine, but nothing is resolving. When I "dig any example.com" I get a SERVFAIL message. Nslookups return no information. Here are my config and zone files. named.conf controls { inet 127.0.0.1 allow { localhost; } keys { coretext-key; }; }; options { listen-on port 53 { any; }; listen-on-v6 port 53 { ::1; }; directory "/var/named"; dump-file "/var/named/data/cache_dump.db"; statistics-file "/var/named/data/named_stats.txt"; memstatistics-file "/var/named/data/named_mem_stats.txt"; // Those options should be used carefully because they disable port // randomization // query-source port 53; // query-source-v6 port 53; allow-query { any; }; allow-query-cache { any; }; }; logging { channel default_debug { file "data/named.run"; severity dynamic; }; }; view "localhost_resolver" { match-clients { 127.0.0.0/24; }; match-destinations { localhost; }; recursion yes; //zone "." IN { // type hint; // file "/var/named/named.ca"; //}; include "/etc/named.rfc1912.zones"; }; view "internal" { /* This view will contain zones you want to serve only to "internal" clients that connect via your directly attached LAN interfaces - "localnets" . */ match-clients { localnets; }; match-destinations { localnets; }; recursion yes; zone "." IN { type hint; file "/var/named/named.ca"; }; // include "/var/named/named.rfc1912.zones"; // you should not serve your rfc1912 names to non-localhost clients. // These are your "authoritative" internal zones, and would probably // also be included in the "localhost_resolver" view above : zone "example.com" { type master; file "data/db.example.com"; }; zone "3.2.1.in-addr.arpa" { type master; file "data/db.1.2.3"; }; }; view "external" { /* This view will contain zones you want to serve only to "external" clients * that have addresses that are not on your directly attached LAN interface subnets: */ match-clients { any; }; match-destinations { any; }; recursion no; // you'd probably want to deny recursion to external clients, so you don't // end up providing free DNS service to all takers allow-query-cache { none; }; // Disable lookups for any cached data and root hints // all views must contain the root hints zone: //include "/etc/named.rfc1912.zones"; zone "." IN { type hint; file "/var/named/named.ca"; }; zone "example.com" { type master; file "data/db.example.com"; }; zone "3.2.1.in-addr.arpa" { type master; file "data/db.1.2.3"; }; }; include "/etc/rndc.key"; db.example.com $TTL 1D ; ; Zone file for example.com ; ; Mandatory minimum for a working domain ; @ IN SOA ns1.example.com. contact.example.com. ( 2011042905 ; serial 8H ; refresh 2H ; retry 4W ; expire 1D ; default_ttl ) NS ns1.example.com. NS ns2.example.com. ns1 A 1.2.3.4 ns2 A 1.2.3.5 example.com. A 1.2.3.4 localhost A 127.0.0.1 www CNAME example.com. mail CNAME example.com. ; db.1.2.3 $TTL 1D $ORIGIN 3.2.1.in-addr.arpa. @ IN SOA ns1.example.com contact.example.com. ( 2011042908 ; 8H ; 2H ; 4W ; 1D ; ) NS ns1.example.com. NS ns2.example.com. 4 PTR hostname.example.com. 5 PTR hostname.example.com. ; Also of note: both of these servers are managed. Tech support is very responsive, and largely useless. Hours go by with them asking me questions to narrow down what could be wrong, then they pass the ticket to the tech on the next shift, who ignores everything that's happened already and spend his whole shift asking all the same questions the last guy asked. So, in summary: *Nameservers, with IPs, are correctly registered with domain registrar *named is configured and running *...and must not be configured correctly, because nothing resolves. Any help would be great. I changed domains and IPs in the files to generics, but let me know if you need to know the domain in question. Thanks! UPDATE I found that I didn't have 127.0.0.1 in /etc/resolv.conf, so I added it, along with my two public IPs that I have named listening on. resolv.conf search www.example.com example.com nameserver 127.0.0.1 nameserver 7.8.9.10 ;Was in here by default, authoritative nameserver of hosting company nameserver 1.2.3.4 ;Public IP #1 nameserver 1.2.3.5 ;Public IP #2 Now when I DIG example.com from the host, it resolves. If I try to DIG from my other server (in the same datacenter), or from the internet, it times out or I get SERVFAIL.

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DNS works only with ip but does not work with NS CentOS + Bind9

- by Borislav Yordanov

I am having a headache with DNS. Lets say my public IP is 1.2.3.4, my local IP is 192.168.0.10 and my domain is example.com I am running CentOS on a virtual machine (Parallels Desktop for Mac) with a LAN card reserved for it, so it gets Ip directly from the router. I have ports 80,443,53 forwarded to 192.168.0.10. Both Mac OS and CentOs firewalls are Off. The strange is when I type dig @1.2.3.4 example.com from my other PC I get: ; <<>> DiG 9.8.3-P1 <<>> @1.2.3.4 example.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16941 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;example.com. IN A ;; ANSWER SECTION: example.com. 86400 IN A 1.2.3.4 ;; AUTHORITY SECTION: example.com. 86400 IN NS ns2.example.com. example.com. 86400 IN NS ns1.example.com. ;; ADDITIONAL SECTION: ns1.example.com. 86400 IN A 1.2.3.4 ns2.example.com. 86400 IN A 1.2.3.4 ;; Query time: 8 msec ;; SERVER: 1.2.3.4#53(1.2.3.4) ;; WHEN: Sat Nov 2 09:37:36 2013 ;; MSG SIZE rcvd: 109 but when i type: dig @ns1.example.com example.com it waits a few seconds and returns dig: couldn't get address for 'ns1.dsht.in': not found This is my config file: /etc/named.conf options { listen-on-v6 { none; }; directory"/var/named"; dump-file"/var/named/data/cache_dump.db"; statistics-file"/var/named/data/named_stats.txt"; memstatistics-file"/var/named/data/named_mem_stats.txt"; allow-query{ localhost; 192.168.0.0/24; }; allow-transfer { localhost; 192.168.0.0/24; }; recursion yes; dnssec-enable yes; dnssec-validation yes; dnssec-lookaside auto; bindkeys-file "/etc/named.iscdlv.key"; managed-keys-directory "/var/named/dynamic"; }; logging { channel default_debug { file "data/named.run"; severity dynamic; }; }; # change all from here view "internal" { match-clients { localhost; 192.168.0.0/24; }; zone "." IN { type hint; file "named.ca"; }; zone "example.com" IN { type master; file "example.com.zone"; allow-update { none; }; }; zone "0.168.192.in-addr.arpa" IN { type master; file "0.168.192.in-addr.arpa"; allow-update { none; }; }; include "/etc/named.rfc1912.zones"; include "/etc/named.root.key"; }; view "external" { match-clients { any; }; allow-query { any; }; recursion no; zone "example.com" IN { type master; file "example.com.zone"; allow-update { none; }; }; zone "4.3.2.1.in-addr.arpa" IN { type master; file "4.3.2.1.in-addr.arpa"; allow-update { none; }; }; }; /var/named/exmaple.com.zone $TTL 86400 @ IN SOA ns1.example.com. host.example.com. ( 2013042201 ;Serial 3600 ;Refresh 1800 ;Retry 604800 ;Expire 86400 ;Minimum TTL ) ; Specify our two nameservers IN NS ns1.example.com. IN NS ns2.example.com. ; Resolve nameserver hostnames to IP, replace with your two droplet IP addresses. ns1 IN A 1.2.3.4 ns2 IN A 1.2.3.4 ; Define hostname -> IP pairs which you wish to resolve @ IN A 1.2.3.4 IN A 1.2.3.4 www IN A 1.2.3.4 server2 IN A 192.168.0.2 * IN A 1.2.3.4 /var/named/4.3.2.1.in-addr.arpa $TTL 2d ; 172800 seconds $ORIGIN 4.3.2.1.IN-ADDR.ARPA. @ IN SOA ns1.example.com. host.example.com. ( 2013010304 ; serial number 3h ; refresh 15m ; update retry 3w ; expiry 3h ; nx = nxdomain ttl ) IN NS ns1.example.com. IN NS ns2.example.com. IN PTR example.com. ; etc /var/named/0.168.192.in-addr.arpa $TTL 2d ; 172800 seconds $ORIGIN 0.168.192.IN-ADDR.ARPA. @ IN SOA ns1.example.com. host.example.com. ( 2013010304 ; serial number 3h ; refresh 15m ; update retry 3w ; expiry 3h ; nx = nxdomain ttl ) IN NS ns1.example.com. IN NS ns2.example.com. 10 IN PTR example.com. 2 IN PTR server2.example.com ; etc I will be very glad if someone can help me. Thank you in advance

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Automating Form Login

- by Greg_Gutkin

Introduction A common task in configuring a web application for proxying in Pagelet Producer is setting up form autologin. PP provides a wizard-like tool for detecting the login form fields, but this is usually only the first step in configuring this feature. If the generated configuration doesn't seem to work, some additional manual modifications will be needed to complete the setup. This article will try to guide you through this process while steering you away from common pitfalls. For the purposes of this article, let's assume the following characteristics about your environment: Web Application Base URL: http://host/app (configured as Resource Source URL in PP) Pagelet Producer Base URL: http://pp/pagelets Form Field Auto-Detection Form Autologin is configured in the PP Admin UI under resource_name/Autologin/Form Login. First, you'll enter the URL to the login form under "Login Form Identification". This will enable the admin wizard to connect to and display the login page. Caution: RedirectsMake sure the entered URL matches what you see in the browser's address bar, when the application login page is displayed. For example, even though you may be able to reach the login page by simply typing http://host/app, the URL you end up on may change to http://host/app/login via browser redirect(s).The second URL is the one you will want to use. Caution: External Login ServersThe login page may actually come from a different server than the application you are trying to proxy. For example, you may notice that the login page URL changes to http://hostB/appB. This is common when external SSO products are involved. There are two ways of dealing with this situation. One is to configure Pagelet Producer to participate in SSO. This approach is out of scope of this article and is discussed in a separate whitepaper (TODO add link). The second approach is to use the autologin feature to provide stored credentials to the SSO login form. Since the login form URL is not an extension of the application base URL (PP resource URL), you will need to add a new PP resource for the SSO server and configure the login form on that resource instead of the original application resource. One side benefit of this additional resource is that it can reused for other applications relying on the same SSO server for login. After entering the login page URL (make sure dropdown says "URL"), click "Automatically Detect Form Fields". This will bring up the web app's login page in a new browser window. Fill it out and submit it as you would normally. If everything goes right, Pagelet Producer will intercept the submitted values and fill out all the needed configuration data in the Admin UI. If the login form window doesn't close or configuration data doesn't get filled in, you may have not entered the login page URL correctly. Review the two cautionary notes above and make any necessary changes. If the form fields got filled automatically, it's time to save the configuration and test it out. If you can access a protected area of the backend application via a proxied PP URL without filling out its login form, then you are pretty much done with login form configuration. The only other step you will need to complete before declaring this aspect of configuration production ready is configuring form field source. You may skip to that section below. Manual Login Form Identification Let's take a closer look at Login Form Identification. This determines how Pagelet Producer recognizes login forms as such. URL The most efficient way of detecting login forms is by looking at the page URL. This method can only be used under the following conditions: Login page URL must be different from the post login application URLs. Login page URL must stay constant regardless of the path it takes to reach the page. For example, reaching the login page by going to the application base URL or to a specific protected URL must result in a redirect to the same login page URL (query string excluded). If only the query string parameters change, just leave out the query string from the configured login page URL. If either of these conditions is not fullfilled, you must switch to the RegEx approach below. RegEx If the login page URL is not uniform enough across all scenarios or is indistinguishable from other page locations, PP can be configured to recognize it by looking at the page markup itself. This is accomplished by changing the dropdown to "RegEx". If regular expressions scare you, take comfort from the fact that in most cases you won't need to enter any special regex characters. Let's look at an example: Say you have a login form that looks like <form id='loginForm' action='login?from=pageA' > <input id='user'> <input id='pass'> </form> Since this form has an id attribute, you can be reasonably sure that this login form can be uniquely identified across the web application by this snippet: "id='loginForm'". (Unless, of course your backend web application contains login forms to other apps). Since no wildcards are needed to find this snippet, you can just enter it as is into the RegEx field - no special regular expression characters needed! If the web developer who created the form wasn't kind enough to provide a unique id, you will need to look for other snippets of the page to uniquely identify it. It could be the action URL, an input field id, or some other markup fragment. You should abstain from using UI text as an identifier it may change in translated versions of the page and prevent the login page logic from working for international users. You may need to turn to regular expression wildcard syntax if no simple matches work. For more information on regular expression, refer to the Resources section. Form Submit Location Now we'll look at the form submit location. If the captured URL contains query string parameters that will likely change from one form submission to the next, you will need to change its type to RegEx. This type will tell Pagelet Producer to parse the login page for the action URL and submit to the value found. The regular expression needs to point at the actual action URL with its first grouping expression. Taking the example form definition above, the form submit location regex would be: action='(.*?)' The parentheses are used to identify the actual action URL, while the rest of the expression provides the context for finding it. Expression .*? is a so-called reluctant wildcard that matches any character excluding the single quote that follows. See Resources section below for further information on regular expressions. Manual Form Field Detection If the Admin UI form field detection wizard fails to populate login form configuration page, you will have to enter the fields by hand. Use a built-in browser developer tool or addon (e.g. Firebug) to inspect the form element and its children input elements. For each input element (including hidden elements), create an entry under Form Fields. Change its Source according to the next section. Form Field Source Change the source of any of the fields not exposed to the users of the login form (i.e. hidden fields) to "Generated". This means Pagelet Producer will just use the values returned by the web app rather than supplying values it stored. For fields that contain sensitive data or vary from user to user (e.g. username & password), change the source to User (Credential) Vault. Logging Support To help you troubleshoot you autologin configuration, PP provides some useful logging support. To turn on detailed logging for the autologin feature, navigate to Settings in Admin UI. Under Logging, change the log level for AutoLogin to Finest. Known Limitations Autologin feature may not work as expected if login form fields (not just the values, but the DOM elements themselves) are generated dynamically by client side JavaScript. Resources RegEx RegEx Reference from Java RegEx Test Tool

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top tweets WebLogic Partner Community – June 2013

- by JuergenKress

Send us your tweets @wlscommunity #WebLogicCommunity and follow us on twitter http://twitter.com/wlscommunity. Please feel free to send us your news! Lucas Jellema ?Getting started with Java EE 7: The Tutorial http://docs.oracle.com/javaee/7/tutorial/doc/home.htm … Simon Haslam I'm looking forward to starting a "WLS on ODA" proof of concept - some ideas for testing: http://www.veriton.co.uk/roller/fmw/entry/virtualised_oda_proof_of_concept … Frank Munz ?It's not too late - I just submitted two presentations about #OracleWebLogic and #Coherence for the @DOAGeV conference in Nürnberg. Did you? Arun Gupta ?Tyrus 1.0 User Guide: https://tyrus.java.net/documentation/1.0/user-guide.html … #WebSocket #JavaEE7 #GlassFish Arun Gupta #JavaEE7 Launch Webinar Technical Breakout replays on Youtube: http://bit.ly/12uUicT JSON 1.0 , EJB .2, Batch 1.0 more coming! OracleBlogs ?FREE Virtual Developer Day: Java SE, Java EE, Java Emebedded on Jun 19th and 25th http://ow.ly/2xBkwV Markus Eisele #Oracle #JavaSE Critical Patch Update Pre-Release Announcement - June 2013 http://www.oracle.com/technetwork/topics/security/javacpujun2013-1899847.html … #security OracleSupport_WLS ?Simple Custom #JMX MBeans with #WebLogic 12c and #Spring http://pub.vitrue.com/3kEr Oracle Technet Building Java HTML5/WebSocket Applications with JSR 356 - 4pm - Grand Ballroom Salon A/B #qconnewyork WebLogic Community Oracle Fusion Middleware (OFM) 11g (11.1.1.7) Starter Kit available & Customizable Demos http://wp.me/p1LMIb-BK Oracle Technet #Java EE 7: Moving Java Forward for the Enterprise | @java http://pub.vitrue.com/tHiM OTNArchBeat ?Oracle Forms to ADF Modernization Reference - Convero (AMEC) Project | @AndrejusB http://pub.vitrue.com/lZPR WebLogic Community ?ExaLogic In Memory Applications & Whitepapers Building Large Scale E-Commerce Platforms & Rethink the Entire Application Lifecycle… WebLogic Community ?Coherence YouTube videos http://wp.me/p1LMIb-BG Arun Gupta ?WARNING: Next 2 days are going to be loaded with #JavaEE7 launch related tweets, and offline next week! JDeveloper & ADF Using Contextual Event in Oracle ADF http://dlvr.it/3Vpybr Oracle WebLogic Check out new blog on #hybrid_cloud & why choice is important http://bit.ly/1b1QGhL Andrejus Baranovskis Oracle Forms to ADF Modernization Reference - Convero (AMEC) Project http://fb.me/1M9iWNmAw WebLogic Community WebLogic on Oracle Database Appliance by Frances Zhao http://wp.me/p1LMIb-BE OTNArchBeat ?New: A-Team Chronicles >> A great resource for technical content covering Oracle Fusion Middleware / Fusion Apps http://pub.vitrue.com/qbzS Oracle for Partners ?Take Java To The Edge: Java Virtual Developer Day – June 19 & June 25 http://bit.ly/19fGlSX Adam Bien ?Looking forward to tomorrow's #javaee7 + #angularjs #html5 marriage at #jpoint. See you there: http://www.jpoint.nl/meetingpoint/editie-2013#sessie-1 … shay shmeltzer ?There is a new patch for the #Oracle #ADF Mobile extension - use help->check for updates to get it. Frank Munz ?Not using @OracleWebLogic 12c yet? Australia does! Reviews from my @AUSOUG workshops in Brisbane, Adelaide and Perth. http://goo.gl/BfVc4 Arun Gupta ?WebSocket, Server-Sent Events, #JavaEE7 sessions accepted at #jaxlondon ... that's gonna be at least third trip to London this year! WebLogic Community SPARC T5-8 Delivers Best Single System SPECjEnterprise2010 Benchmark running WebLogic 12c http://wp.me/p1LMIb-BC WebLogic Community The Ultimate Java EE Event - 16 Power Workshops mit allen wichtigen Java-EE-Themen http://wp.me/p1LMIb-BY Oracle WebLogic ?@OracleWebLogic 7 Jun New Blog Post: Using try-with-resources with JDBC objects http://ow.ly/2xryb5 JDeveloper & ADF Switching Lists of Values http://dlvr.it/3PbCkw WebLogic Community ?YouTube channel Learning Oracle's ADF http://wp.me/p1LMIb-zA Markus Eisele [GER] RT @heisedc: #Java-Entwicklung in #Oracles Public #Cloud http://heise.de/-1866388/ftw OracleBlogs ?Coherence Incubator & Community Source Code & Release Documentation http://ow.ly/2x2fXK chriscmuir ?New blog post: Migrating ADF Mobile apps from 1.0 to 1.1 https://blogs.oracle.com/onesizedoesntfitall/entry/migrating_adf_mobile_apps_from … JDeveloper & ADF ?ADF JavaScript Partitioning for Performance http://dlvr.it/3Trw15 WebLogic Community WebLogic Server Security Workshop June 27th 2013 Germany http://wp.me/p1LMIb-C7 WebLogic Community Oracle Optimized Solution for WebLogic Server 12c http://wp.me/p1LMIb-BA WebLogic Community Virtualize and Run Your Forms Applications in the Cloud - Now On Demand http://wp.me/p1LMIb-By Lucas Jellema Innteresting presentation on various aspects of end user assistance in Fusion Applications (ADF based): http://www.slideshare.net/uobroin/ouag-ireland-final2012slideshare … Adam Bien ?Summer Of JavaEE Workshops And Gigs: Free Hacking night:11.06.2013, Utrecht JavaEE 7 Meets HTML 5 and AngularJ... http://bit.ly/11XRjt4 WebLogic Community ?Real World ADF Design & Architecture Principles Trainings Germany, Poland & Portugal http://wp.me/p1LMIb-Bw Oracle for Partners ?JAVA Virtual Developer Day – June 19 & June 25 - Watch educational content and engage with Oracle experts online https://oracle.6connex.com/portal/java2013/login/?langR=en_US&mcc=OPNNSL … Markus Eisele ?[blog] Java EE 7 is final. Thoughts, Insights and further Pointers. http://dlvr.it/3SrxnB #javaee7 WebLogic Community Oracle takes the top spot for market share in the Application Server Market Segment for 2012 http://wp.me/p1LMIb-Bu OTNArchBeat ?Oracle ACE Director @LucasJellema is "very pleasantly surprised" with the new ADF Academy. http://pub.vitrue.com/8fad chriscmuir ?Sell out crowd for our ADF architecture course in Munich #adfarch pic.twitter.com/zhNtQJ25JV Markus Eisele ?[blog] New German Article: Java 7 Update 21 Security Improvements http://dlvr.it/3Sc8V9 #java #heise #security Markus Eisele ?[blog] New German Article: Oracle Java Cloud Service http://dlvr.it/3Sc20V #java #heise #OracleCloud OracleSupport_WLS ?Troubleshooting and Tuning with #WebLogic - Developer Webcast now available on #Youtube http://pub.vitrue.com/GSOy Andrejus Baranovskis New ADF Academy - Impressive Concept for ADF eLearning http://fb.me/2kYSMKKR5 OracleSupport_WLS ?Removing a #weblogic domain properly http://pub.vitrue.com/ZndM WebLogic Community WebLogic Partner Community Newsletter May 2013 http://wp.me/p1LMIb-Bp Oracle WebLogic ?Blog: Troubleshooting tools Part 3- Heap Dumps #Oracle #WebLogic Read the series http://bit.ly/14CQSD2 Oracle WebLogic ?Blog: #WebLogic_Server on #Oracle_Database_Appliance- How to conjure a WebLogic cluster- http://bit.ly/11fciHA Oracle WebLogic ?Check out new cool features in Oracle Traffic Director- http://bit.ly/11fbz9h WebLogic Community Additional new material WebLogic Community April 2013 http://wp.me/p1LMIb-zM WebLogic Community New WebLogic references - we want yours http://wp.me/p1LMIb-zK OracleSupport_WLS ?#Weblogic Session Replication jsession ID and F5 http://pub.vitrue.com/dWZp OracleBlogs ?top tweets WebLogic Partner Community May 2013 http://ow.ly/2xc8M5 WebLogic Community Welcome to the Spring edition of Oracle Scene http://wp.me/p1LMIb-zE Andreas Koop ?[blog post] ADF: Static Values View Object does not show any values (solved) http://bit.ly/14RDZ8p OracleBlogs ?ADF Mobile - accessing the SQLite database http://ow.ly/2x85r0 OracleSupport_WLS Youtube channel- Troubleshooting and Tuning with #WebLogic.#JRockit #SOAP #JRF http://pub.vitrue.com/qMxu Arun Gupta Next Java Magazine is all about #JavaEE7...productivity, HTML5, WebSocket, Batch & more. Subscribe http://ow.ly/lkD5D (@Oraclejavamag) Oracle WebLogic How to configure a #WebLogic cluster on #Oracle_Database_Appliance? It’s easy, read how. http://bit.ly/11fciHA Oracle WebLogic ?Blog: How to use Heap Dumps to troubleshooting memory leaks- #Oracle #WebLogic_Server http://bit.ly/14CQSD2 OracleBlogs ?Over 100 Images To Be Added to NetBeans Platform Showcase http://ow.ly/2x7Fvp Lucas Jellema A new release of the ADF EMG Task Flow Tester is now available for both JDeveloper 11 R1 and R2. https://java.net/projects/adf-task-flow-tester/pages/GettingStarted … WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: twitter,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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T-SQL Dynamic SQL and Temp Tables

- by George

It looks like #temptables created using dynamic SQL via the EXECUTE string method have a different scope and can't be referenced by "fixed" SQLs in the same stored procedure. However, I can reference a temp table created by a dynamic SQL statement in a subsequence dynamic SQL but it seems that a stored procedure does not return a query result to a calling client unless the SQL is fixed. A simple 2 table scenario: I have 2 tables. Let's call them Orders and Items. Order has a Primary key of OrderId and Items has a Primary Key of ItemId. Items.OrderId is the foreign key to identify the parent Order. An Order can have 1 to n Items. I want to be able to provide a very flexible "query builder" type interface to the user to allow the user to select what Items he want to see. The filter criteria can be based on fields from the Items table and/or from the parent Order table. If an Item meets the filter condition including and condition on the parent Order if one exists, the Item should be return in the query as well as the parent Order. Usually, I suppose, most people would construct a join between the Item table and the parent Order tables. I would like to perform 2 separate queries instead. One to return all of the qualifying Items and the other to return all of the distinct parent Orders. The reason is two fold and you may or may not agree. The first reason is that I need to query all of the columns in the parent Order table and if I did a single query to join the Orders table to the Items table, I would be repoeating the Order information multiple times. Since there are typically a large number of items per Order, I'd like to avoid this because it would result in much more data being transfered to a fat client. Instead, as mentioned, I would like to return the two tables individually in a dataset and use the two tables within to populate a custom Order and child Items client objects. (I don't know enough about LINQ or Entity Framework yet. I build my objects by hand). The second reason I would like to return two tables instead of one is because I already have another procedure that returns all of the Items for a given OrderId along with the parent Order and I would like to use the same 2-table approach so that I could reuse the client code to populate my custom Order and Client objects from the 2 datatables returned. What I was hoping to do was this: Construct a dynamic SQL string on the Client which joins the orders table to the Items table and filters appropriate on each table as specified by the custom filter created on the Winform fat-client app. The SQL build on the client would have looked something like this: TempSQL = " INSERT INTO #ItemsToQuery OrderId, ItemsId FROM Orders, Items WHERE Orders.OrderID = Items.OrderId AND /* Some unpredictable Order filters go here */ AND /* Some unpredictable Items filters go here */ " Then, I would call a stored procedure, CREATE PROCEDURE GetItemsAndOrders(@tempSql as text) Execute (@tempSQL) --to create the #ItemsToQuery table SELECT * FROM Items WHERE Items.ItemId IN (SELECT ItemId FROM #ItemsToQuery) SELECT * FROM Orders WHERE Orders.OrderId IN (SELECT DISTINCT OrderId FROM #ItemsToQuery) The problem with this approach is that #ItemsToQuery table, since it was created by dynamic SQL, is inaccessible from the following 2 static SQLs and if I change the static SQLs to dynamic, no results are passed back to the fat client. 3 around come to mind but I'm look for a better one: 1) The first SQL could be performed by executing the dynamically constructed SQL from the client. The results could then be passed as a table to a modified version of the above stored procedure. I am familiar with passing table data as XML. If I did this, the stored proc could then insert the data into a temporary table using a static SQL that, because it was created by dynamic SQL, could then be queried without issue. (I could also investigate into passing the new Table type param instead of XML.) However, I would like to avoid passing up potentially large lists to a stored procedure. 2) I could perform all the queries from the client. The first would be something like this: SELECT Items.* FROM Orders, Items WHERE Order.OrderId = Items.OrderId AND (dynamic filter) SELECT Orders.* FROM Orders, Items WHERE Order.OrderId = Items.OrderId AND (dynamic filter) This still provides me with the ability to reuse my client sided object-population code because the Orders and Items continue to be returned in two different tables. I have a feeling to, that I might have some options using a Table data type within my stored proc, but that is also new to me and I would appreciate a little bit of spoon feeding on that one. If you even scanned this far in what I wrote, I am surprised, but if so, I woul dappreciate any of your thoughts on how to accomplish this best.

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Random Page Cost and Planning

- by Dave Jarvis

A query (see below) that extracts climate data from weather stations within a given radius of a city using the dates for which those weather stations actually have data. The query uses the table's only index, rather effectively: CREATE UNIQUE INDEX measurement_001_stc_idx ON climate.measurement_001 USING btree (station_id, taken, category_id); Reducing the server's configuration value for random_page_cost from 2.0 to 1.1 had a massive performance improvement for the given range (nearly an order of magnitude) because it suggested to PostgreSQL that it should use the index. While the results now return in 5 seconds (down from ~85 seconds), problematic lines remain. Bumping the query's end date by a single year causes a full table scan: sc.taken_start >= '1900-01-01'::date AND sc.taken_end <= '1997-12-31'::date AND How do I persuade PostgreSQL to use the indexes regardless of years between the two dates? (A full table scan against 43 million rows is probably not the best plan.) Find the EXPLAIN ANALYSE results below the query. Thank you! Query SELECT extract(YEAR FROM m.taken) AS year, avg(m.amount) AS amount FROM climate.city c, climate.station s, climate.station_category sc, climate.measurement m WHERE c.id = 5182 AND earth_distance( ll_to_earth(c.latitude_decimal,c.longitude_decimal), ll_to_earth(s.latitude_decimal,s.longitude_decimal)) / 1000 <= 30 AND s.elevation BETWEEN 0 AND 3000 AND s.applicable = TRUE AND sc.station_id = s.id AND sc.category_id = 1 AND sc.taken_start >= '1900-01-01'::date AND sc.taken_end <= '1996-12-31'::date AND m.station_id = s.id AND m.taken BETWEEN sc.taken_start AND sc.taken_end AND m.category_id = sc.category_id GROUP BY extract(YEAR FROM m.taken) ORDER BY extract(YEAR FROM m.taken) 1900 to 1996: Index "Sort (cost=1348597.71..1348598.21 rows=200 width=12) (actual time=2268.929..2268.935 rows=92 loops=1)" " Sort Key: (date_part('year'::text, (m.taken)::timestamp without time zone))" " Sort Method: quicksort Memory: 32kB" " -> HashAggregate (cost=1348586.56..1348590.06 rows=200 width=12) (actual time=2268.829..2268.886 rows=92 loops=1)" " -> Nested Loop (cost=0.00..1344864.01 rows=744510 width=12) (actual time=0.807..2084.206 rows=134893 loops=1)" " Join Filter: ((m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (sc.station_id = m.station_id))" " -> Nested Loop (cost=0.00..12755.07 rows=1220 width=18) (actual time=0.502..521.937 rows=23 loops=1)" " Join Filter: ((sec_to_gc(cube_distance((ll_to_earth((c.latitude_decimal)::double precision, (c.longitude_decimal)::double precision))::cube, (ll_to_earth((s.latitude_decimal)::double precision, (s.longitude_decimal)::double precision))::cube)) / 1000::double precision) <= 30::double precision)" " -> Index Scan using city_pkey1 on city c (cost=0.00..2.47 rows=1 width=16) (actual time=0.014..0.015 rows=1 loops=1)" " Index Cond: (id = 5182)" " -> Nested Loop (cost=0.00..9907.73 rows=3659 width=34) (actual time=0.014..28.937 rows=3458 loops=1)" " -> Seq Scan on station_category sc (cost=0.00..970.20 rows=3659 width=14) (actual time=0.008..10.947 rows=3458 loops=1)" " Filter: ((taken_start >= '1900-01-01'::date) AND (taken_end <= '1996-12-31'::date) AND (category_id = 1))" " -> Index Scan using station_pkey1 on station s (cost=0.00..2.43 rows=1 width=20) (actual time=0.004..0.004 rows=1 loops=3458)" " Index Cond: (s.id = sc.station_id)" " Filter: (s.applicable AND (s.elevation >= 0) AND (s.elevation <= 3000))" " -> Append (cost=0.00..1072.27 rows=947 width=18) (actual time=6.996..63.199 rows=5865 loops=23)" " -> Seq Scan on measurement m (cost=0.00..25.00 rows=6 width=22) (actual time=0.000..0.000 rows=0 loops=23)" " Filter: (m.category_id = 1)" " -> Bitmap Heap Scan on measurement_001 m (cost=20.79..1047.27 rows=941 width=18) (actual time=6.995..62.390 rows=5865 loops=23)" " Recheck Cond: ((m.station_id = sc.station_id) AND (m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (m.category_id = 1))" " -> Bitmap Index Scan on measurement_001_stc_idx (cost=0.00..20.55 rows=941 width=0) (actual time=5.775..5.775 rows=5865 loops=23)" " Index Cond: ((m.station_id = sc.station_id) AND (m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (m.category_id = 1))" "Total runtime: 2269.264 ms" 1900 to 1997: Full Table Scan "Sort (cost=1370192.26..1370192.76 rows=200 width=12) (actual time=86165.797..86165.809 rows=94 loops=1)" " Sort Key: (date_part('year'::text, (m.taken)::timestamp without time zone))" " Sort Method: quicksort Memory: 32kB" " -> HashAggregate (cost=1370181.12..1370184.62 rows=200 width=12) (actual time=86165.654..86165.736 rows=94 loops=1)" " -> Hash Join (cost=4293.60..1366355.81 rows=765061 width=12) (actual time=534.786..85920.007 rows=139721 loops=1)" " Hash Cond: (m.station_id = sc.station_id)" " Join Filter: ((m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end))" " -> Append (cost=0.00..867005.80 rows=43670150 width=18) (actual time=0.009..79202.329 rows=43670079 loops=1)" " -> Seq Scan on measurement m (cost=0.00..25.00 rows=6 width=22) (actual time=0.001..0.001 rows=0 loops=1)" " Filter: (category_id = 1)" " -> Seq Scan on measurement_001 m (cost=0.00..866980.80 rows=43670144 width=18) (actual time=0.008..73312.008 rows=43670079 loops=1)" " Filter: (category_id = 1)" " -> Hash (cost=4277.93..4277.93 rows=1253 width=18) (actual time=534.704..534.704 rows=25 loops=1)" " -> Nested Loop (cost=847.87..4277.93 rows=1253 width=18) (actual time=415.837..534.682 rows=25 loops=1)" " Join Filter: ((sec_to_gc(cube_distance((ll_to_earth((c.latitude_decimal)::double precision, (c.longitude_decimal)::double precision))::cube, (ll_to_earth((s.latitude_decimal)::double precision, (s.longitude_decimal)::double precision))::cube)) / 1000::double precision) <= 30::double precision)" " -> Index Scan using city_pkey1 on city c (cost=0.00..2.47 rows=1 width=16) (actual time=0.012..0.014 rows=1 loops=1)" " Index Cond: (id = 5182)" " -> Hash Join (cost=847.87..1352.07 rows=3760 width=34) (actual time=6.427..35.107 rows=3552 loops=1)" " Hash Cond: (s.id = sc.station_id)" " -> Seq Scan on station s (cost=0.00..367.25 rows=7948 width=20) (actual time=0.004..23.529 rows=7949 loops=1)" " Filter: (applicable AND (elevation >= 0) AND (elevation <= 3000))" " -> Hash (cost=800.87..800.87 rows=3760 width=14) (actual time=6.416..6.416 rows=3552 loops=1)" " -> Bitmap Heap Scan on station_category sc (cost=430.29..800.87 rows=3760 width=14) (actual time=2.316..5.353 rows=3552 loops=1)" " Recheck Cond: (category_id = 1)" " Filter: ((taken_start >= '1900-01-01'::date) AND (taken_end <= '1997-12-31'::date))" " -> Bitmap Index Scan on station_category_station_category_idx (cost=0.00..429.35 rows=6376 width=0) (actual time=2.268..2.268 rows=6339 loops=1)" " Index Cond: (category_id = 1)" "Total runtime: 86165.936 ms"

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MySQL for Excel 1.1.3 has been released

- by Javier Treviño

The MySQL Windows Experience Team is proud to announce the release of MySQL for Excel version 1.1.3, the latest addition to the MySQL Installer for Windows. MySQL for Excel is an application plug-in enabling data analysts to very easily access and manipulate MySQL data within Microsoft Excel. It enables you to directly work with a MySQL database from within Microsoft Excel so you can easily do tasks such as: Importing MySQL Data into Excel Exporting Excel data directly into MySQL to a new or existing table Editing MySQL data directly within Excel MySQL for Excel is installed using the MySQL Installer for Windows. The MySQL installer comes in 2 versions Full (150 MB) which includes a complete set of MySQL products with their binaries included in the download Web (1.5 MB - a network install) which will just pull MySQL for Excel over the web and install it when run. You can download MySQL Installer from our official Downloads page at http://dev.mysql.com/downloads/installer/. MySQL for Excel 1.1.3 introduces the following features: Upon saving a Workbook containing Worksheets in Edit Mode, the user is asked if he wants to exit the Edit Mode on all Worksheets before their parent Workbook is saved so the Worksheets are saved unprotected, otherwise the Worksheets will remain protected and the users will be able to unprotect them later retrieving the passkeys from the application log after closing MySQL for Excel. Added background coloring to the column names header row of an Import Data operation to have the same look as the one in an Edit Data operation (i.e. gray-ish background). Connection passwords can be stored securely just like MySQL Workbench does and these secured passwords are shared with Workbench in the same way connections are. Changed the way the MySQL for Excel ribbon toggle button works, instead of just showing or hiding the add-in it actually opens and closes it. Added a connection test before any operation against the database (schema creation, data import, append, export or edition) so the operation dialog is not shown and a friendlier error message is shown. Also this release contains the following bug fixes: Added a check on every connection test for an expired password, if the password has been expired a dialog is now shown to the user to reset the password. Bug #17354118 - DON'T HANDLE EXPIRED PASSWORDS Added code to escape text values to be imported to an Excel worksheet that start with an equals sign so Excel does not treat those values as formulas that will fail evaluation. This is an option turned on by default that can be turned off by users if they wish to import values to be treated as Excel formulas. Bug #17354102 - ERROR IMPORTING TEXT VALUES TO EXCEL STARTING WITH AN EQUALS SIGN Added code to properly check the reason for a failing connection, if it's a failing password the user gets a dialog to retry the connection with a different password until the connection succeeds, a connection error not related to the password is thrown or the user cancels. If the failing connection is not related to a bad password an error message is shown to the users indicating the reason of the failure. Bug #16239007 - CONNECTIONS TO MYSQL SERVICES NOT RUNNING DISPLAY A WRONG PASSWORD ERROR MESSAGE Added global options dialog that can be accessed from the Schema Selection and DB Object Selection panels where the timeouts for the connection to the DB Server and for the query commands can be changed from their default values (15 seconds for the connection timeout and 30 seconds for the query timeout). MySQL Bug #68732, Bug #17191646 - QUERY TIMEOUT CANNOT BE ADJUSTED IN MYSQL FOR EXCEL Changed the Varchar(65,535) data type shown in the Export Data data type combo box to Text since the maximum row size is 65,535 bytes and any autodetected column data type with a length greater than 4,000 should be set to Text actually for the table to be created successfully. MySQL Bug #69779, Bug #17191633 - EXPORT FAILS FOR EXCEL FILES CONTAINING > 4000 CHARACTERS OF TEXT PER CELL Removed code that was replacing all spaces typed by the user in an overriden data type for a new column in an Export Data operation, also improved the data type detection code to flag as invalid data types with parenthesis but without any text inside or where the contents inside the parenthesis are not valid for the specific data type. Bug #17260260 - EXPORT DATA SET TYPE NOT WORKING WITH MEMBER VALUES CONTAINING SPACES Added support for the year data type with a length of 2 or 4 and a validation that valid values are integers between 1901-2155 (for 4-digit years) or between 0-99 (for 2-digit years). Bug #17259915 - EXPORT DATA YEAR DATA TYPE NOT RECOGNIZED IF DECLARED WITH A DISPLAY WIDTH) Fixed code for Export Data operations where users overrode the data type for columns typing Text in the data type combobox, which is a valid data type but was not recognized as such. Bug #17259490 - EXPORT DATA TEXT DATA TYPE NOT RECOGNIZED AS A VALID DATA TYPE Changed the location of the registry where the MySQL for Excel add-in is installed to HKEY_LOCAL_MACHINE instead of HKEY_CURRENT_USER so the add-in is accessible by all users and not only to the user that installed it. For this to work with Excel 2007 a hotfix may be required (see http://support.microsoft.com/kb/976477). MySQL Bug #68746, Bug #16675992 - EXCEL-ADD-IN IS ONLY INSTALLED FOR USER ACCOUNT THAT THE INSTALLATION RUNS UNDER Added support for Excel 2013 Single Document Interface, now that Excel 2013 creates 1 window per workbook also the Excel Add-In maintains an independent custom task pane in each window. MySQL Bug #68792, Bug #17272087 - MYSQL FOR EXCEL SIDEBAR DOES NOT APPEAR IN EXCEL 2013 (WITH WORKAROUND) Included the latest MySQL Utility with a code fix for the COM exception thrown when attempting to open Workbench in the Manage Connections window. Bug #17258966 - MYSQL WORKBENCH NOT OPENED BY CLICKING MANAGE CONNECTIONS HOTLABEL Fixed code for Append Data operations that was not applying a calculated automatic mapping correctly when the source and target tables had different number of columns, some columns with the same name but some of those lying on column indexes beyond the limit of the other source/target table. MySQL Bug #69220, Bug #17278349 - APPEND DOESN'T AUTOMATICALLY DETECT EXCEL COL HEADER WITH SAME NAME AS SQL FIELD Fixed some code for Edit Data operations that was escaping special characters twice (during edition in Excel and then upon sending the query to the MySQL server). MySQL Bug #68669, Bug #17271693 - A BACKSLASH IS INSERTED BEFORE AN APOSTROPHE EDITING TABLE WITH MYSQL FOR EXCEL Upgraded MySQL Utility with latest version that encapsulates dialog base classes and introduces more classes to handle Workbench connections, and removed these from the Excel project. Bug #16500331 - CAN'T DELETE CONNECTIONS CREATED WITHIN ADDIN You can access the MySQL for Excel documentation at http://dev.mysql.com/doc/refman/5.6/en/mysql-for-excel.html You can find our team’s blog at http://blogs.oracle.com/MySQLOnWindows. You can also post questions on our MySQL for Excel forum found at http://forums.mysql.com/. Enjoy and thanks for the support!

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python list mysteriously getting set to something within my django/piston handler

- by Anverc

To start, I'm very new to python, let alone Django and Piston. Anyway, I've created a new BaseHandler class "class BaseApiHandler(BaseHandler)" so that I can extend some of the stff that BaseHandler does. This has been working fine until I added a new filter that could limit results to the first or last result. Now I can refresh the api page over and over and sometimes it will limit the result even if I don't include /limit/whatever in my URL... I've added some debug info into my return value to see what is happening, and that's when it gets more weird. this return value will make more sense after you see the code, but here they are for reference: When the results are correct: "statusmsg": "2 hours_detail found with query: {'empid':'22','datestamp':'2009-03-02',}", when the results are incorrect (once you read the code you'll notice two things wrong. First, it doesn't have 'limit':'None', secondly it shouldn't even get this far to begin with. "statusmsg": "1 hours_detail found with query: {'empid':'22','datestamp':'2009-03-02',with limit[0,1](limit,None),}", It may be important to note that I'm the only person with access to the server running this right now, so even if it was a cache issue, it doesn't make sense that I can just refresh and get different results by hitting F5 while viewing: http://localhost/api/hours_detail/datestamp/2009-03-02/empid/22 Here's the code broken into urls.py and handlers.py so that you can see what i'm doing: URLS.PY urlpatterns = patterns('', #hours_detail/id/{id}/empid/{empid}/projid/{projid}/datestamp/{datestamp}/daterange/{fromdate}to{todate}/limit/{first|last}/exact #empid is required # id, empid, projid, datestamp, daterange can be in any order url(r'^api/hours_detail/(?:' + \ r'(?:[/]?id/(?P<id>\d+))?' + \ r'(?:[/]?empid/(?P<empid>\d+))?' + \ r'(?:[/]?projid/(?P<projid>\d+))?' + \ r'(?:[/]?datestamp/(?P<datestamp>\d{4,}[-/\.]\d{2,}[-/\.]\d{2,}))?' + \ r'(?:[/]?daterange/(?P<daterange>(?:\d{4,}[-/\.]\d{2,}[-/\.]\d{2,})(?:to|/-)(?:\d{4,}[-/\.]\d{2,}[-/\.]\d{2,})))?' + \ r')+' + \ r'(?:/limit/(?P<limit>(?:first|last)))?' + \ r'(?:/(?P<exact>exact))?$', hours_detail_resource), HANDLERS.PY # inherit from BaseHandler to add the extra functionality i need to process the possibly null URL params class BaseApiHandler(BaseHandler): # keep track of the handler so the data is represented back to me correctly post_name = 'base' # THIS IS THE LIST IN QUESTION - SOMETIMES IT IS GETTING SET TO [0,1] MYSTERIOUSLY # this gets set to a list when the results are to be limited limit = None def has_limit(self): return (isinstance(self.limit, list) and len(self.limit) == 2) def process_kwarg_read(self, key, value, d_post, b_exact): """ this should be overridden in the derived classes to process kwargs """ pass # override 'read' so we can better handle our api's searching capabilities def read(self, request, *args, **kwargs): d_post = {'status':0,'statusmsg':'Nothing Happened'} try: # setup the named response object # select all employees then filter - querysets are lazy in django # the actual query is only done once data is needed, so this may # seem like some memory hog slow beast, but it's actually not. d_post[self.post_name] = self.queryset(request) # this is a string that holds debug information... it's the string I mentioned before pasting this code s_query = '' b_exact = False if 'exact' in kwargs and kwargs['exact'] <> None: b_exact = True s_query = '\'exact\':True,' for key,value in kwargs.iteritems(): # the regex url possibilities will push None into the kwargs dictionary # if not specified, so just continue looping through if that's the case if value == None or key == 'exact': continue # write to the s_query string so we have a nice error message s_query = '%s\'%s\':\'%s\',' % (s_query, key, value) # now process this key/value kwarg self.process_kwarg_read(key=key, value=value, d_post=d_post, b_exact=b_exact) # end of the kwargs for loop else: if self.has_limit(): # THIS SEEMS TO GET HIT SOMETIMES IF YOU CONSTANTLY REFRESH THE API PAGE, EVEN THOUGH # THE LINE IN THE FOR LOOP WHICH UPDATES s_query DOESN'T GET HIS AND THUS self.process_kwarg_read ALSO # DOESN'T GET HIT SO NEITHER DOES limit = [0,1] s_query = '%swith limit[%s,%s](limit,%s),' % (s_query, self.limit[0], self.limit[1], kwargs['limit']) d_post[self.post_name] = d_post[self.post_name][self.limit[0]:self.limit[1]] if d_post[self.post_name].count() == 0: d_post['status'] = 0 d_post['statusmsg'] = '%s not found with query: {%s}' % (self.post_name, s_query) else: d_post['status'] = 1 d_post['statusmsg'] = '%s %s found with query: {%s}' % (d_post[self.post_name].count(), self.post_name, s_query) except: e = sys.exc_info()[1] d_post['status'] = 0 d_post['statusmsg'] = 'error: %s' % e d_post[self.post_name] = [] return d_post class HoursDetailHandler(BaseApiHandler): #allowed_methods = ('GET',) model = HoursDetail exclude = () post_name = 'hours_detail' def process_kwarg_read(self, key, value, d_post, b_exact): if ... # I have several if/elif statements here that check for other things... # 'self.limit =' only shows up in the following elif: elif key == 'limit': order_by = 'clock_time' if value == 'last': order_by = '-clock_time' d_post[self.post_name] = d_post[self.post_name].order_by(order_by) # TO GET HERE, THE ONLY PLACE IN CODE WHERE self.limit IS SET, YOU MUST HAVE GONE THROUGH # THE value == None CHECK???? self.limit = [0, 1] else: raise NameError def read(self, request, *args, **kwargs): # empid is required, so make sure it exists before running BaseApiHandler's read method if not('empid' in kwargs and kwargs['empid'] <> None and kwargs['empid'] >= 0): return {'status':0,'statusmsg':'empid cannot be empty'} else: return BaseApiHandler.read(self, request, *args, **kwargs) Does anyone have a clue how else self.limit might be getting set to [0, 1] ? Am I misunderstanding kwargs or loops or anything in Python?

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I see no LOBs!

- by Paul White

Is it possible to see LOB (large object) logical reads from STATISTICS IO output on a table with no LOB columns? I was asked this question today by someone who had spent a good fraction of their afternoon trying to work out why this was occurring – even going so far as to re-run DBCC CHECKDB to see if any corruption had taken place. The table in question wasn’t particularly pretty – it had grown somewhat organically over time, with new columns being added every so often as the need arose. Nevertheless, it remained a simple structure with no LOB columns – no TEXT or IMAGE, no XML, no MAX types – nothing aside from ordinary INT, MONEY, VARCHAR, and DATETIME types. To add to the air of mystery, not every query that ran against the table would report LOB logical reads – just sometimes – but when it did, the query often took much longer to execute. Ok, enough of the pre-amble. I can’t reproduce the exact structure here, but the following script creates a table that will serve to demonstrate the effect: IF OBJECT_ID(N'dbo.Test', N'U') IS NOT NULL DROP TABLE dbo.Test GO CREATE TABLE dbo.Test ( row_id NUMERIC IDENTITY NOT NULL, col01 NVARCHAR(450) NOT NULL, col02 NVARCHAR(450) NOT NULL, col03 NVARCHAR(450) NOT NULL, col04 NVARCHAR(450) NOT NULL, col05 NVARCHAR(450) NOT NULL, col06 NVARCHAR(450) NOT NULL, col07 NVARCHAR(450) NOT NULL, col08 NVARCHAR(450) NOT NULL, col09 NVARCHAR(450) NOT NULL, col10 NVARCHAR(450) NOT NULL, CONSTRAINT [PK dbo.Test row_id] PRIMARY KEY CLUSTERED (row_id) ) ; The next script loads the ten variable-length character columns with one-character strings in the first row, two-character strings in the second row, and so on down to the 450th row: WITH Numbers AS ( -- Generates numbers 1 - 450 inclusive SELECT TOP (450) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) INSERT dbo.Test WITH (TABLOCKX) SELECT REPLICATE(N'A', N.n), REPLICATE(N'B', N.n), REPLICATE(N'C', N.n), REPLICATE(N'D', N.n), REPLICATE(N'E', N.n), REPLICATE(N'F', N.n), REPLICATE(N'G', N.n), REPLICATE(N'H', N.n), REPLICATE(N'I', N.n), REPLICATE(N'J', N.n) FROM Numbers AS N ORDER BY N.n ASC ; Once those two scripts have run, the table contains 450 rows and 10 columns of data like this: Most of the time, when we query data from this table, we don’t see any LOB logical reads, for example: -- Find the maximum length of the data in -- column 5 for a range of rows SELECT result = MAX(DATALENGTH(T.col05)) FROM dbo.Test AS T WHERE row_id BETWEEN 50 AND 100 ; But with a different query… -- Read all the data in column 1 SELECT result = MAX(DATALENGTH(T.col01)) FROM dbo.Test AS T ; …suddenly we have 49 LOB logical reads, as well as the ‘normal’ logical reads we would expect. The Explanation If we had tried to create this table in SQL Server 2000, we would have received a warning message to say that future INSERT or UPDATE operations on the table might fail if the resulting row exceeded the in-row storage limit of 8060 bytes. If we needed to store more data than would fit in an 8060 byte row (including internal overhead) we had to use a LOB column – TEXT, NTEXT, or IMAGE. These special data types store the large data values in a separate structure, with just a small pointer left in the original row. Row Overflow SQL Server 2005 introduced a feature called row overflow, which allows one or more variable-length columns in a row to move to off-row storage if the data in a particular row would otherwise exceed 8060 bytes. You no longer receive a warning when creating (or altering) a table that might need more than 8060 bytes of in-row storage; if SQL Server finds that it can no longer fit a variable-length column in a particular row, it will silently move one or more of these columns off the row into a separate allocation unit. Only variable-length columns can be moved in this way (for example the (N)VARCHAR, VARBINARY, and SQL_VARIANT types). Fixed-length columns (like INTEGER and DATETIME for example) never move into ‘row overflow’ storage. The decision to move a column off-row is done on a row-by-row basis – so data in a particular column might be stored in-row for some table records, and off-row for others. In general, if SQL Server finds that it needs to move a column into row-overflow storage, it moves the largest variable-length column record for that row. Note that in the case of an UPDATE statement that results in the 8060 byte limit being exceeded, it might not be the column that grew that is moved! Sneaky LOBs Anyway, that’s all very interesting but I don’t want to get too carried away with the intricacies of row-overflow storage internals. The point is that it is now possible to define a table with non-LOB columns that will silently exceed the old row-size limit and result in ordinary variable-length columns being moved to off-row storage. Adding new columns to a table, expanding an existing column definition, or simply storing more data in a column than you used to – all these things can result in one or more variable-length columns being moved off the row. Note that row-overflow storage is logically quite different from old-style LOB and new-style MAX data type storage – individual variable-length columns are still limited to 8000 bytes each – you can just have more of them now. Having said that, the physical mechanisms involved are very similar to full LOB storage – a column moved to row-overflow leaves a 24-byte pointer record in the row, and the ‘separate storage’ I have been talking about is structured very similarly to both old-style LOBs and new-style MAX types. The disadvantages are also the same: when SQL Server needs a row-overflow column value it needs to follow the in-row pointer a navigate another chain of pages, just like retrieving a traditional LOB. And Finally… In the example script presented above, the rows with row_id values from 402 to 450 inclusive all exceed the total in-row storage limit of 8060 bytes. A SELECT that references a column in one of those rows that has moved to off-row storage will incur one or more lob logical reads as the storage engine locates the data. The results on your system might vary slightly depending on your settings, of course; but in my tests only column 1 in rows 402-450 moved off-row. You might like to play around with the script – updating columns, changing data type lengths, and so on – to see the effect on lob logical reads and which columns get moved when. You might even see row-overflow columns moving back in-row if they are updated to be smaller (hint: reduce the size of a column entry by at least 1000 bytes if you hope to see this). Be aware that SQL Server will not warn you when it moves ‘ordinary’ variable-length columns into overflow storage, and it can have dramatic effects on performance. It makes more sense than ever to choose column data types sensibly. If you make every column a VARCHAR(8000) or NVARCHAR(4000), and someone stores data that results in a row needing more than 8060 bytes, SQL Server might turn some of your column data into pseudo-LOBs – all without saying a word. Finally, some people make a distinction between ordinary LOBs (those that can hold up to 2GB of data) and the LOB-like structures created by row-overflow (where columns are still limited to 8000 bytes) by referring to row-overflow LOBs as SLOBs. I find that quite appealing, but the ‘S’ stands for ‘small’, which makes expanding the whole acronym a little daft-sounding…small large objects anyone? © Paul White 2011 email: [email protected] twitter: @SQL_Kiwi

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pass an ID with hyperlik but cant get this ID value from a fk in one table when i click in insert

- by susan

Something strange happened in my codes, actually I have a hyperlink that pass ID value in a query string to second page.in second page i have 2 sql datasource that both these sql datasources should get this id value and pass it to a filter parameter to show sth in datalist. so in another word I have a first page that has an hyperlink read ID value from a datasource and pass it to second page.its like below: <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%# "~/forumpage.aspx?ID="+Eval("ID")%>'><%#Eval("title")%> </asp:HyperLink> then in second page i have one sql datasource with a query like this ...where ID=@id and get this id in query string from db.it work great . but i have problem with second sql datasource in second page it has a query sth like below:...forms.question_id=@id then in sql reference both to query string as ID that get by first page in hyperlink. but when i click in insert button show me error with fk. error:Error:The INSERT statement conflicted with the FOREIGN KEY constraint "FK_forumreply_forumquestions". The conflict occurred in database "forum", table "dbo.forumquestions", column 'ID'. The statement has been terminated. my tables (question(ID,user_id(fk),Cat_id(fk),title,bodytext) (reply(ID,userr_id(fk),questionn_id(fk),titlereply,bodytestreply); When by hand in cb i gave a number in questionn_id like 1 it show me successful but when it want read from a filter by datasource this field face with problem. plzzzz help i really need skip from this part.and cause i am new i guess I cant understand the logic way clearly. <asp:SqlDataSource ID="sdsreply" runat="server" ConnectionString="<%$ ConnectionStrings:forumConnectionString %>" SelectCommand="SELECT forumreply.ID, forumreply.userr_id, forumreply.questionn_id, forumreply.bodytextreply, forumreply.datetimereply, forumquestions.ID AS Expr1, forumusers.ID AS Expr2, forumusers.username FROM forumquestions INNER JOIN forumreply ON forumquestions.ID = forumreply.questionn_id INNER JOIN forumusers ON forumquestions.user_id = forumusers.ID AND forumreply.userr_id = forumusers.ID where forumreply.questionn_id=@questionn_id"> <SelectParameters> <asp:QueryStringParameter Name="questionn_id" QueryStringField="ID" /> </SelectParameters> </asp:SqlDataSource> it is cb for second page in insert button: { if (Session["userid"] != null) { lblreply.Text = Session["userid"].ToString(); } else { Session["userid"]=null; } if (HttpContext.Current.User.Identity.IsAuthenticated) { lblshow.Text = string.Empty; string d = HttpContext.Current.User.Identity.Name; lblshow.Text =d + "???? ??? ?????." ; foreach (DataListItem item in DataList2.Items) { Label questionn_idLabel = (Label)item.FindControl("questionn_idLabel"); Label userr_idLabel = (Label)item.FindControl("userr_idLabel"); lbltest.Text = string.Empty; lbltest.Text = questionn_idLabel.Text; lblreply.Text = string.Empty; lblreply.Text = userr_idLabel.Text; } } else { lblshow.Text = "??? ??? ??? ??? ?? ?? ?????? ???? ???? ???? ????? ??? ??? ? ??? ????? ???????."; } } { if(HttpContext.Current.User.Identity.IsAuthenticated) { if (Page.IsValid) { SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["forumConnectionString"].ConnectionString); try { con.Open(); SqlCommand cmd = new SqlCommand("insert into forumreply (userr_id,questionn_id,bodytextreply,datetimereply)values(@userr_id,@questionn_id,@bodytextreply,@datetimereply)", con); cmd.Parameters.AddWithValue("userr_id",lblreply.Text); cmd.Parameters.AddWithValue("questionn_id",lbltest.Text); cmd.Parameters.AddWithValue("bodytextreply",txtbody.Text); cmd.Parameters.AddWithValue("datetimereply",DateTime.Now ); cmd.ExecuteNonQuery(); } catch (Exception exp) { Response.Write("<b>Error:</b>"); Response.Write(exp.Message); } finally { con.Close(); } lblmsg.Text = "???? ??? ?? ?????? ??? ?????.thx"; lblshow.Visible = false; //lbltxt.Text = txtbody.Text; txtbody.Text = string.Empty; } } else { lblmsg.Text = string.Empty; Session["rem"] = Request.UrlReferrer.AbsoluteUri; Response.Redirect("~/login.aspx"); } }

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