Search Results

Search found 21433 results on 858 pages for 'query execution plans'.

Page 96/858 | < Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >

• Amazon Web Services Free Trial: query about get and put requests

  - by abel

  Amazon recently introduced a free tier for its cloud offering. I signed up for AWS and while signing up for the free tier of S3, i found this As part of AWS Free Usage Tier, you can get started with Amazon S3 for free. Upon sign-up, new AWS customers receive 5 GB of Amazon S3 storage, 20,000 Get Requests, 2,000 Put Requests, 15GB of bandwidth in and 15GB of bandwidth out each month for one year. source:aws.amazon.com , emphasis mine. 20,000 GET requests & 2000 puts mean , 20,000 page views(max) and 2000 file uploads per month. Isn't that lower than what App Engine offers 43,200,000 requests per day.Am I missing some thing, please help.

  Read the article

• In WMI, can I use a join (or something similar) to acquire the IisWebServer object for a site, given

  - by Precipitous

  Given a server name and a physical path, I'd like to be able to hunt down the IISWebServer object and ApplicationPool. Website url is also an acceptable input. Our technologies are IIS 6, WMI, and access via C# or Powershell 2. I'm certain this would be easier with IIS 7 its managed API. We don't have that yet. Here's what I can do: Get a list of IIS virtual directories from IISWebVirtualDirSetting and filter (offline) for the matching physical path. $theVirtualDir = gwmi -Namespace "root/MicrosoftIISv2" ` -ComputerName $servername -authentication PacketPrivacy ` -class "IISWebVirtualDirSetting" ` | where-object {$_.Path -like $deployLocation} From the virtual directory object, I can get a name (like W3SVC/40565456/root). Given this name, I can get to other goodies, such as the IIS web server object. gwmi -Namespace "root/MicrosoftIISv2" ` -ComputerName $servername ` -authentication PacketPrivacy ` -Query "SELECT * FROM IisWebServer WHERE Name='W3SVC/40589473'" The questions, restated: 1) This is a query language. Can I join or subquery so that 1 WMI query statement gets web servers based on IISWebVirtualDir.Path? How? 2) In solving 1, you'll have to explain how to query on the Path property. Why is this an invalid query? "SELECT * FROM IISWebVirtualDirSetting WHERE Path='D:\sites\globaldominator'"

  Read the article

• c++ exceptions and program execution logic

  - by Andrew

  Hello everyone, I have been thru a few questions but did not find an answer. I wonder how should the exception handling be implemented in a C++ software so it is centralized and it is tracking the software progress? For example, I want to process exceptions at four stages of the program and know that exception happened at that specific stage: 1. Initialization 2. Script processing 3. Computation 4. Wrap-up. At this point, I tried this: int main (...) { ... // start logging system try { ... } catch (exception &e) { cerr << "Error: " << e.what() << endl; cerr << "Could not start the logging system. Application terminated!\n"; return -1; } catch(...) { cerr << "Unknown error occured.\n"; cerr << "Could not start the logging system. Application terminated!\n"; return -2; } // open script file and acquire data try { ... } catch (exception &e) { cerr << "Error: " << e.what() << endl; cerr << "Could not acquire input parameters. Application terminated!\n"; return -1; } catch(...) { cerr << "Unknown error occured.\n"; cerr << "Could not acquire input parameters. Application terminated!\n"; return -2; } // computation try { ... } ... This is definitely not centralized and seems stupid. Or maybe it is not a good concept at all?

  Read the article

• bash command history update before execution of command

  - by Jon

  Hi, Bash's command history is great, especially it is useful when adding the history -a command to the COMMAND_PROMPT. However, I'm wondering if there is a way to log the commands to a file as soon as the Return key is pressed, e.g. before starting the command and not on completion of the command (using the COMMAND_PROMPT option would save the command once the prompt is there again). I read about auditing programs like snoopy and session recorder like script but I thought they're already too complex for the simple question I have. I guess that deactivating that script logs all the output of the command would lead already in the right direction but isn't there a quicker way to solve that probelm? Thanks, Jon

  Read the article

• curl halts script execution

  - by Funky Dude

  my script uses curl to upload images to smugsmug site via smugsmug api. i loop through a folder and upload every image in there. but after 3-4 uploads, curl_exec would fail, stopped everything and prevent other images from uploading. $upload_array = array( "method" => "smugmug.images.upload", "SessionID" => $session_id, "AlbumID" => $alb_id, "FileName" => zerofill($n, 3) . ".jpg", "Data" => base64_encode($data), "ByteCount" => strlen($data), "MD5Sum" => $data_md5); $ch = curl_init(); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0); curl_setopt($ch, CURLOPT_POSTFIELDS, $upload_array); curl_setopt( $ch, CURLOPT_URL, "https://upload.smugmug.com/services/api/rest/1.2.2/"); $upload_result = curl_exec($ch); //fails here curl_close($ch); updated: so i added logging into my script. when it does fail, the logging stops after fwrite($fh, "begin curl\n"); fwrite($fh, "begin curl\n"); $upload_result = curl_exec($ch); fwrite($fh, "curl executed\n"); fwrite($fh, "curl info: ".print_r(curl_getinfo($ch,true))."\n"); fwrite($fh, "xml dump: $upload_result \n"); fwrite($fh, "curl error: ".curl_error($ch)."\n"); i also curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 60*60);

  Read the article

• Using The Data Mining Query Task in SSIS

  SQL Server Integration Services (SSIS) is a Business Intelligence tool which can be used by database developers or administrators to perform Extract, Transform & Load (ETL) operations. In my previous article Using Analysis Services Processing Task & Analysis Services ... [Read Full Article]

  Read the article

• Get list of named queries in NHibernate

  - by Dan

  I have a dozen or so named queries in my NHibernate project and I want to execute them against a test database in unit tests to make sure the syntax still matches the changing domain/database model. Currently I have a unit test for each named query where I get and execute the query, for example: IQuery query = session.GetNamedQuery("GetPersonSummaries"); var personSummaryArray = query.List(); Assert.That(personSummaryArray, Is.Not.Null); This works fine, but I would like to have one unit test that loops thru all of the named queries and executes them. Is there a way to discover all of the available named queries? Thanks Dan

  Read the article

• mySQL Left Join on multiple tables

  - by Jarrod

  Hi I'm really struggling with this query. I have 4 tables (http://oberto.co.nz/db-sql.png): Invoice_Payement, Invoice, Client and Calendar. I'm trying to create a report by summing up the 'paid_amount' col, in Invoice_Payment, by month/year. The query needs to include all months, even those with no data There query needs the condition (Invoice table): registered_id = [id] I have tried with the below query, which works, but falls short when 'paid_date' does not have any records for a month. The outcome is that month does not show in the results I added a Calendar table to resolved this but not sure how to left join to it. SELECT MONTHNAME(Invoice_Payments.date_paid) as month, SUM(Invoice_Payments.paid_amount) AS total FROM Invoice, Client, Invoice_Payments WHERE Client.registered_id = 1 AND Client.id = Invoice.client_id And Invoice.id = Invoice_Payments.invoice_id AND date_paid IS NOT NULL GROUP BY YEAR(Invoice_Payments.date_paid), MONTH(Invoice_Payments.date_paid) Please see the above link for a basic ERD diagram of my scenario. Thanks for reading. I've posted this Q before but I think I worded it badly.

  Read the article

• Threading cost - minimum execution time when threads would add speed

  - by Lukas

  I am working on a C# application that works with an array. It walks through it (meaning that at one time only a narrow part of the array is used). I am considering adding threads in it to make it perform faster (it runs on a dualcore computer). The problem is that I do not know if it would actually help, because threads cost something and this cost could easily be more than the parallel gain... So how do I determine if threading would help?

  Read the article

• Dynamic filter expressions in an OpenAccess LINQ query

  We had some support questions recently where our customers had the need to combine multiple smaller predicate expressions with either an OR or an AND  logical operators (these will be the || and && operators if you are using C#). And because the code from the answer that we sent to these customers is very interesting, and can easily be refactorred into something reusable, we decided to write this blog post. The key thing that one must know is that if you want your predicate to be translated by OpenAccess ORM to SQL and executed on the server you must have a LINQ Expression that is not compiled. So, let’s say that you have these smaller predicate expressions: Expression<Func<Customer, bool>> filter1 = c => c.City.StartsWith("S");Expression<Func<Customer, bool>> filter2 = c => c.City.StartsWith("M");Expression<Func<Customer, bool>> filter3 = c => c.ContactTitle == "Owner"; And ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• Strange execution of get accesor in c#?

  - by Kenji Kina

  I set up a simple program just to test how the code inside a get accessor executes (since I had been having some issues in another project), and found something quite strange: class Program { static void Main(string[] args) { var test = new TestClass(); var testBool = test.TestBool; } } public class TestClass { private bool _testBool = true; public bool TestBool { get { if (_testBool) { Console.WriteLine("true!"); } else { Console.WriteLine("false! WTF!"); } _testBool = false; return _testBool; } } } I expected the output to be true! But what I got instead was true! false! WTF! Just what is going on here?

  Read the article

• Difference between KeywordQuery, FullTextQuerySearch type for Object Model and Web service Query

  - by Raghu

  Initially I believed these 3 to be doing more or less the same thing with just the notation being different. Until recently, when i noticed that their does exists a big difference between the results of the KeyWordQuery/FullTextQuerySearch and Web service Query. I used both KeywordQuery and FullText method to search of the the value of a customColumn XYZ with value (ASDSADA-21312ASD-ASDASD):- When I run this query as:- FullTextSqlQuery:- FullTextSqlQuery myQuery = new FullTextSqlQuery(site); { // Construct query text String queryText = "Select title, path, author, isdocument from scope() where freetext('ASDSADA-21312ASD-ASDASD') "; myQuery.QueryText = queryText; myQuery.ResultTypes = ResultType.RelevantResults; }; // execute the query and load the results into a datatable ResultTableCollection queryResults = myQuery.Execute(); ResultTable resultTable = queryResults[ResultType.RelevantResults]; // Load table with results DataTable queryDataTable = new DataTable(); queryDataTable.Load(resultTable, LoadOption.OverwriteChanges); I get the following result representing the document. * Title: TestPDF * path: http://SharepointServer/Shared Documents/Forms/DispForm.aspx?ID=94 * author: null * isDocument: false Do note the Path and isDocument fields of the above result. Web Service Method Then I tried a Web Service Query method. I used Sharepoint Search Service Tool available at http://sharepointsearchserv.codeplex.com/ and ran the same query i.e. Select title, path, author, isdocument from scope() where freetext('ASDSADA-21312ASD-ASDASD'). This time I got the following results:- * Title: TestPDF * path: http://SharepointServer/Shared Documents/TestPDF.pdf * author: null * isDocument: true Again note the path. While the search results from 2nd method are useful as they provide me the file path exactly, I can't seem to understand why is the method 1 not giving me the same results? Why is there a discrepancy between the two results?

  Read the article

• Running mysql query using node blocks the whole process and then timesout

  - by lobengula3rd

  I have a node javascript that uses mysql npm (Felix). I have a procedure stored in my DB which I call when the user selects an option to kind of create its own instance of the program. The user chooses for how long he wants that data to be initialized for him. This is suppsoed to be between 1 and 2 years. So if he choose 1 year this query will insert around 20,000 rows into 1 table. If I run this query and a local DB this takes around 30 seconds (I suppose it is reasonable because its a big query which should be done only once in 1 or 2 years so its ok). For some reason my node script freezes as if it can't handle any more calls from other users. The even worse problem is that after like 2 minutes my client ui gets like an error from the server. At this point not all the data that was supposed to enter the DB is entered. After waiting like another minute all the data finally gets to the DB and only then it will accept new requests. This is my connection: this.connection = mysql.createConnection({ host : '********rds.amazonaws.com', user : 'admin', password : '******', database : '*****' }); and this is my query function: this.createCourts = function (req, res, next){ connection.query('CALL filldates("' + req.body['startDate'] + '","' + req.body['endDate'] + '","' + req.body['numOfCourts'] + '","' + req.body['duration'] + '","' + req.body['sundayOpen'] + '","' + req.body['mondayOpen'] + '","' + req.body['tuesdayOpen'] + '","' + req.body['wednesdayOpen'] + '","' + req.body['thursdayOpen'] + '","' + req.body['fridayOpen'] + '","' + req.body['saturdayOpen'] + '","' + req.body['sundayClose'] + '","' + req.body['mondayClose'] + '","' + req.body['tuesdayClose'] + '","' + req.body['wednesdayClose'] + '","' + req.body['thursdayClose'] + '","' + req.body['fridayClose'] + '","' + req.body['saturdayClose'] + '");', function(err){ if (err){ console.log(err); } else return res.send(200); }); }; what am i missing here? as i understand connection.query should by async so why is it actually blocking my node script? thanks.

  Read the article

• Foreign/accented characters in sql query

  - by FromCanada

  I'm using Java and Spring's JdbcTemplate class to build an SQL query in Java that queries a Postgres database. However, I'm having trouble executing queries that contain foreign/accented characters. For example the (trimmed) code: JdbcTemplate select = new JdbcTemplate( postgresDatabase ); String query = "SELECT id FROM province WHERE name = 'Ontario';"; Integer id = select.queryForObject( query, Integer.class ); will retrieve the province id, but if instead I did name = 'Québec' then the query fails to return any results (this value is in the database so the problem isn't that it's missing). I believe the source of the problem is that the database I am required to use has the default client encoding set to SQL_ASCII, which according to this prevents automatic character set conversions. (The Java environments encoding is set to 'UTF-8' while I'm told the database uses 'LATIN1' / 'ISO-8859-1') I was able to manually indicate the encoding when the resultSets contained values with foreign characters as a solution to a previous problem with a similar nature. Ex: String provinceName = new String ( resultSet.getBytes( "name" ), "ISO-8859-1" ); But now that the foreign characters are part of the query itself this approach hasn't been successful. (I suppose since the query has to be saved in a String before being executed anyway, breaking it down into bytes and then changing the encoding only muddles the characters further.) Is there a way around this without having to change the properties of the database or reconstruct it? PostScript: I found this function on StackOverflow when making up a title, it didn't seem to work (I might not have used it correctly, but even if it did work it doesn't seem like it could be the best solution.):

  Read the article

• Funky Behavior NoTracking Query Entities

  I’ve been using a lot of NoTracking queries to grab lists of data that I don’t need change tracked. It enhances performance and cuts down on resources. There are some nuances about these entities, however. One of the interesting behaviors of EF4’s Lazy Loading is that even if you have entities that you have queried with NoTracking on, they will still lazy load related entities. Unless you’ve read this somewhere (it’s on the ADO.NET team’s blog post which introduces...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• JPA native query join returns object but dereference throws class cast exception

  - by masato-san

  I'm using JPQL Native query to join table and query result is stored in List<Object[]>. public String getJoinJpqlNativeQuery() { String final SQL_JOIN = "SELECT v1.bitbit, v1.numnum, v1.someTime, t1.username, t1.anotherNum FROM MasatosanTest t1 JOIN MasatoView v1 ON v1.username = t1.username;" System.out.println("get join jpql native query is being called ============================"); EntityManager em = null; List<Object[]> out = null; try { em = EmProvider.getDefaultManager(); Query query = em.createNativeQuery(SQL_JOIN); out = query.getResultList(); System.out.println("return object ==========>" + out); System.out.println(out.get(0)); String one = out.get(0).toString(); //LINE 77 where ClassCastException System.out.println(one); } catch(Exception e) { } finally { if(em != null) { em.close; } } } The problem is System.out.println("return object ==========>" + out); outputs: return object ==========> [[true, 0, 2010-12-21 15:32:53.0, masatosan, 0.020], [false, 0, 2010-12-21 15:32:53.0, koga, 0.213]] System.out.println(out.get(0)) outputs: [true, 0, 2010-12-21 15:32:53.0, masatosan, 0.020] So I assumed that I can assign return value of out.get(0) which should be String: String one = out.get(0).toString(); But I get weird ClassCastException. java.lang.ClassCastException: java.util.Vector cannot be cast to [Ljava.lang.Object; at local.test.jaxrs.MasatosanTestResource.getJoinJpqlNativeQuery (MasatosanTestResource.java:77) So what's really going on? Even Object[] foo = out.get(0); would throw an ClassCastException :(

  Read the article

• Force 'Replace Into' to use a certain index

  - by Bobby

  I have a MySQL (5.0) table with 3 rows which are considered a combined Unique Index: CREATE TABLE `test`.`table_a` ( `Id` int(11) NOT NULL AUTO_INCREMENT, `field1` varchar(5) COLLATE latin1_swedish_ci NOT NULL DEFAULT '', `field2` varchar(5) COLLATE latin1_swedish_ci NOT NULL DEFAULT '', `field3` varchar(5) COLLATE latin1_swedish_ci NOT NULL DEFAULT '', PRIMARY KEY (`Id`), INDEX `IdxUnqiue` (`field1`(5),`field2`(5),`field3`(5)) ) ENGINE=MyISAM; This table should be filled with a REPLACE INTO query: REPLACE INTO table_a ( Field1, Field2, Field3 ) VALUES ( "Test1", "Test2", "Test3" ) The behavior I'd like to see is that this query always overrides the previous inserted row, because IdxUnique is...ahm, triggered. But unfortunately, there's still the primary index which seems to kick in and always inserts a new row. What I get: Query was executed 3 times: +---Id---+---Field1---+---Field2---+---Field3---+ | 1 | Test1 | Test2 | Test2 | | 2 | Test1 | Test2 | Test2 | | 3 | Test1 | Test2 | Test2 | +--------+------------+------------+------------+ What I want: Query was executed 3 times: +---Id---+---Field1---+---Field2---+---Field3---+ | 3 | Test1 | Test2 | Test2 | +--------+------------+------------+------------+ So, can I tell REPLACE INTO to use just a certain Index or to consider one 'more inportant' then another?

  Read the article

• Need some help with a MySQL subquery count

  - by Ferdy

  I'm running into my own limits of MySQL query skills, so I hope some SQL guru can help out on this one. The situation is as follow: I have images that can be tagged. As you might expect this is stored in three tables: Image Tag Tag_map (maps images to tags) I have a SQL query that calculates the related tags based on a tag id. The query basically checks what other tags were used for images for images using that tag. Example: Image1 tagged as "Bear" Image2 tagged as "Bear" and "Canada" If I throw "Bear" (or its tag id) at the query, it will return "Canada". This works fine. Here's the query: SELECT tag.name, tag.id, COUNT(tag_map.id) as cnt FROM tag_map,tag WHERE tag_map.tag_id = tag.id AND tag.id != '185' AND tag_map.image_id IN (SELECT tag_map.image_id FROM tag_map INNER JOIN tag ON tag_map.tag_id = tag.id WHERE tag.id = '185') GROUP BY tag_map.id LIMIT 0,100 The part I'm stuck with is the count. For each related tag returned, I want to know how many images are in that tag. Currently it always returns 1, even if there are for example 3. I've tried counting different columns all resulting in the same output, so I guess there is a flaw in my thinking.

  Read the article

• Linq to Sql get SqlCommand when stored procedure execution fails

  - by Tim Mahy

  Hi all, currently I'm assigning a TextWriter to the Log property of my Linq to Sql data context (per request instancing) and write this to my logging when an exception is thrown while executing a stored procedure (is strongly typed mapped in the context, so not executing a custom command) however when using ADO.NET we normally inspect the SqlCommand upon unhandled exception to read out the parameters and log them is it possible to access the SqlCommand that was used for executing a Stored Procedure in L2S so we can reuse that existing logging component? This would be far nicer than the current Log TextWriter solution.... greetings, Tim

  Read the article

• WPF BackgroundWorker Execution

  - by Sanju

  Hi All, I've been programming C# for a while now (I'm a Computer Science major), and have never had to implement threading. I am currently building an application for a client that requires threading for a series of operations. Due to the nature of the client/provider agreement, I cannot release the source I am working with. The code that I have posted is in a general form. Pretty much the basic idea of what I am implementing, excluding the content specific source. The first Snippet demonstrates my basic structure, The Progress class is a custom progress window that is displayed as a dialog to prevent user UI interaction. I am currently using the code to complete database calls based on a collection of objects in another area of the application code. For example, I have a collection of "Objects" of one of my custom classes, that I perform these database calls on or on behalf of. My current set up works just fine when I call the "GeneralizedFunction" one and only one time. What I need to do is call this function once for every object in the collection. I was attempting to use a foreach loop to iterate through the collection, then I tried a for loop. For both loops, the result was the same. The Async operation performs exactly as desired for the first item in the collection. This, however, is the only one it works for. For each subsequent item, the progress box (my custom window) displays and immediately closes. In terms of the database calls, the calls for the first item in the collection are the only ones that successfully complete. All others aren't attempted. I've tried everything that I know and don't know to do, but I just cannot seem to get it to work. How can I get this to work for my entire collection? Any and all help is very greatly appreciated. Progress progress; BackgroundWorker worker; // Cancel the current process private void CancelProcess(object sender, EventArgs e) { worker.CancelAsync(); } // The main process ... "Generalized" private void GeneralizedFunction() { progress = new Progress(); progress.Cancel += CancelProcess; progress.Owner = this; Dispatcher pDispatcher = progress.Dispatcher; worker = new BackgroundWorker(); worker.WorkerSupportsCancellation = true; object[] workArgs = { arg1, arg2, arg3}; worker.DoWork += delegate(object s, DoWorkEventArgs args) { /* All main logic here */ foreach(Class ClassObject in ClassObjectCollection) { //Some more logic here UpdateProgressDelegate update = new UpdateProgressDelegate(updateProgress); pDispatcher.BeginInvoke(update, arg1,arg2,arg3); Thread.Sleep(1000); } }; worker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args) { progress.Close(); }; worker.RunWorkerAsync(workArgs); progress.ShowDialog(); } public delegate void UpdateProgressDelegate(arg1,arg2,arg3); private void updateProgress(arg1,arg2,arg3) { //Update progress }

  Read the article

• OData Query Option top Forces Data To Be Sorted By Primary Key

  This post show a simple WCF Data Service (Formerly known as ADO.NET Data Services) project that retrieves data using the Reflection Provider for accessing data. It goes on to show that using $top... This site is a resource for asp.net web programming. It has examples by Peter Kellner of techniques for high performance programming...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• Database EAV model, record listing as per search

  - by Shyam Sunder Verma

  I am building a dynamic application. I have three tables : ( EAV model style) 1: Items ( ItemId, ItemName) 2: Fields (FieldId, FieldName) 3: Field Values ( ItemID, FieldId, Value) Can you tell me how to write SINGLE query to get starting 20 records from ALL items where FieldId=4 is equal to TRUE. Expected Result : Columns = ItemID | Name | Field1 | Field2 | Field3 Each Row= ItemId | ItemName| Value1 | Value2 | Value3 Important concerns : 1: Number of fields per item are not known 2: I need one to write ONE query. 3: Query will be running on 100K records, so performance is concern. 4: I am using MySQL 5.0, so need solution for MYSQL Should I denormalize the tables if above query is not possible at all ? Any advice ?

  Read the article

• .Net long-running scheduled code execution

  - by Prof Plum

  I am working on a couple of projects now where I really wish there was some sort of component that I could specify a time and date, and then execute some sort of method. DateTime date = new DateTime(x,x,x,x,x,x); ScheduledMethod sMethod = new ScheduledMethod(date, [method delegate of some sort]); \\at the specified date, sMethod invokes [method delegate of some sort] I know that I can do this with Windows Workflow Foundation as a long running process, which is good for certain things, but are there any alternatives? Workflow is not exactly straight forward with the details, and it would be nice to be able to deploy something more simple for light weight tasks. An example would be a method that checks a network folder once a day and deletes any files that are more than 30 days old. I realize that this may be pie in the sky dreaming, but this would be extremely useful for automating certain mundane maintinence tasks (scheduled sql operations, file system cleansing, routine email sending, etc.). It does not necessarily have to be .Net, but that is where I am coming from. Any ideas?

  Read the article

• Understanding run time code interpretation and execution

  - by Bob

  I'm creating a game in XNA and was thinking of creating my own scripting language (extremely simple mind you). I know there's better ways to go about this (and that I'm reinventing the wheel), but I want the learning experience more than to be productive and fast. When confronted with code at run time, from what I understand, the usual approach is to parse into a machine code or byte code or something else that is actually executable and then execute that, right? But, for instance, when Chrome first came out they said their JavaScript engine was fast because it compiles the JavaScript into machine code. This implies other engines weren't compiling into machine code. I'd prefer not compiling to a lower language, so are there any known modern techniques for parsing and executing code without compiling to low level? Perhaps something like parsing the code into some sort of tree, branching through the tree, and comparing each symbol and calling some function that handles that symbol? (Wild guessing and stabbing in the dark)

  Read the article

• MySql: Query multiple identical dynamic tables.

  - by JYelton

  I have a database with 500+ tables, each with identical structure, that contain historical data from sensors. I am trying to come up with a query that will locate, for example, all instances where sensor n exceeds x. The problem is that the tables are dynamic, the query must be able to dynamically obtain the list of tables. I can query information_schema.tables to get a list of the tables, like so: SELECT table_name FROM information_schema.tables WHERE table_schema = 'database_name'; I can use this to create a loop in the program and then query the database repeatedly, however it seems like there should be a way to have MySql do the multiple table search. I have not been able to make a stored procedure that works, but the examples I can find are generally for searching for a string in any column. I want to specifically find data in a specific column that exists in all tables. I admit I do not understand how to properly use stored procedures nor if they are the appropriate solution to this problem. An example query inside the loop would be: SELECT device_name, sensor_value FROM device_table WHERE sensor_value > 10; Trying the following does not work: SELECT device_name, sensor_value FROM ( SELECT table_name FROM information_schema.tables WHERE table_schema = 'database_name' ) WHERE sensor_value > 10; It results in an error: "Every derived table must have its own alias." The goal is to have a list of all devices that have had a given sensor value occur anywhere in their log (table). Ultimately, should I just loop in my program once I've obtained a list of tables, or is there a query structure that would be more efficient?

  Read the article

< Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >