Search Results

Search found 28985 results on 1160 pages for 'sql training'.

Page 1121/1160 | < Previous Page | 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128  | Next Page >

• MSMQ - Message Queue Abstraction and Pattern

  - by Maxim Gershkovich

  Hi All, Let me define the problem first and why a messagequeue has been chosen. I have a datalayer that will be transactional and EXTREMELY insert heavy and rather then attempt to deal with these issues when they occur I am hoping to implement my application from the ground up with this in mind. I have decided to tackle this problem by using the Microsoft Message Queue and perform inserts as time permits asynchronously. However I quickly ran into a problem. Certain inserts that I perform may need to be recalled (ie: retrieved) immediately (imagine this is for POS system and what happens if you need to recall the last transaction - one that still hasn’t been inserted). The way I decided to tackle this problem is by abstracting the MessageQueue and combining it in my data access layer thereby creating the illusion of a single set of data being returned to the user of the datalayer (I have considered the other issues that occur in such a scenario (ie: essentially dirty reads and such) and have concluded for my purposes I can control these issues). However this is where things get a little nasty... I’ve worked out how to get the messages back and such (trivial enough problem) but where I am stuck is; how do I create a generic (or at least somewhat generic) way of querying my message queue? One where I can minimize the duplication between the SQL queries and MessageQueue queries. I have considered using LINQ (but have very limited understanding of the technology) and have also attempted an implementation with Predicates which so far is pretty smelly. Are there any patterns for such a problem that I can utilize? Am I going about this the wrong way? Does anyone have an of their own ideas about how I can tackle this problem? Does anyone even understand what I am talking about? :-) Any and ALL input would be highly appreciated and seriously considered… Thanks again.

  Read the article

• SQLAlchemy, one to many vs many to one

  - by sadvaw

  Dear Everyone, I have the following data: CREATE TABLE `groups` ( `bookID` INT NOT NULL, `groupID` INT NOT NULL, PRIMARY KEY(`bookID`), KEY( `groupID`) ); and a book table which basically has books( bookID, name, ... ), but WITHOUT groupID. There is no way for me to determine what the groupID is at the time of the insert for books. I want to do this in sqlalchemy. Hence I tried mapping Book to the books joined with groups on book.bookID=groups.bookID. I made the following: tb_groups = Table( 'groups', metadata, Column('bookID', Integer, ForeignKey('books.bookID'), primary_key=True ), Column('groupID', Integer), ) tb_books = Table( 'books', metadata, Column('bookID', Integer, primary_key=True), tb_joinedBookGroup = sql.join( tb_books, tb_groups, \ tb_books.c.bookID == tb_groups.c.bookID) and defined the following mapper: mapper( Group, tb_groups, properties={ 'books': relation(Book, backref='group') }) mapper( Book, tb_joinedBookGroup ) ... However, when I execute this piece of code, I realized that each book object has a field groups, which is a list, and each group object has books field which is a singular assigment. I think my definition here must have been causing sqlalchemy to be confused about the many-to-one vs one-to-many relationship. Can someone help me sort this out? My desired goal is g.books = [b, b, b, .. ] book.group = g, where g is an instance of group, and b is an instance of book

  Read the article

• Displaying a collection of objects in a .Net grid on a smartphone without data binding.

  - by Xav

  I know there's No DataGridView in the CF, but I've got a collection of in-memory objects that I want to display in a grid on a phone. Options I have thought of: Stick all the objects into a SQL-CE database and use a bound datagrid. This'll mean pulling my classes apart and separating the data from the functionality, which may or may not be a bad thing, but seems a little overkill. Write my own dataset and binding code so that I can bind my collection of objects to a bound datagrid. No idea how practical or possible this is, but seems like it's either do-able or impossible and I'm hoping someone here knows which! Find a third-party unbound grid control. The only one I've seen mentioned is OpenNetCF, which I'm downloading as I type. Are there others? Are any of them any good? Do something very nasty with dynamically loading labels and textboxes into a scrolling region on the form. REALLY don't want to go there. I'm not much experienced with data-bound controls other than occasionally making use of the very vanilla functionality in WinForms or ASP.Net, and that quite a long time ago, so if any of the above are silly, please be gentle. Thanks Xav

  Read the article

• LINQ .Cast() extension method fails but (type)object works.

  - by Ben Robinson

  To convert between some LINQ to SQL objects and DTOs we have created explicit cast operators on the DTOs. That way we can do the following: DTOType MyDTO = (LinqToSQLType)MyLinq2SQLObj; This works well. However when you try to cast using the LINQ .Cast() extension method it trows an invalid cast exception saying cannot cast type Linq2SQLType to type DTOType. i.e. the below does not work List<DTO.Name> Names = dbContact.tNames.Cast<DTO.Name>() .ToList(); But the below works fine: DAL.tName MyDalName = new DAL.tName(); DTO.Name MyDTOName = (DTO.Name)MyDalName; and the below also works fine List<DTO.Name> Names = dbContact.tNames.Select(name => (DTO.Name)name) .ToList(); Why does the .Cast() extension method throw an invalid cast exception? I have used the .Cast() extension method in this way many times in the past and when you are casting something like a base type to a derived type it works fine, but falls over when the object has an explicit cast operator.

  Read the article

• Currently using View, Should I use a hard table instead?

  - by 1001010101

  I am currently debating whether my table, mapping_uGroups_uProducts, which is a view formed by the following table: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `db`.`mapping_uGroups_uProducts` AS select distinct `X`.`upID` AS `upID`,`Z`.`ugID` AS `ugID` from ((`db`.`mapping_uProducts_Products` `X` join `db`.`productsInfo` `Y` on((`X`.`pID` = `Y`.`pID`))) join `db`.`mapping_uGroups_Groups` `Z` on((`Y`.`gID` = `Z`.`gID`))); My current query is: SELECT upID FROM uProductsInfo \ JOIN fs_uProducts USING (upID) column \ JOIN mapping_uGroups_uProducts USING (upID) -- could be faster if we use hard table and index \ JOIN mapping_fs_key USING (fsKeyID) \ WHERE fsName="OVERALL" \ AND ugID=1 \ ORDER BY score DESC \ LIMIT 0,30; which is pretty slow. (for 30 results, it requires about 10 secondes). I think the reason for my query being so slow is definitely due to the fact that that particular query relies on a VIEW which has no index to speed things up. +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ | 1 | PRIMARY | mapping_fs_key | const | PRIMARY,fsName | fsName | 386 | const | 1 | Using temporary; Using filesort | | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 19706 | Using where | | 1 | PRIMARY | uProductsInfo | eq_ref | PRIMARY | PRIMARY | 4 | mapping_uGroups_uProducts.upID | 1 | Using index | | 1 | PRIMARY | fs_uProducts | ref | upID | upID | 4 | db.uProductsInfo.upID | 221 | Using where | | 2 | DERIVED | X | ALL | PRIMARY | NULL | NULL | NULL | 40772 | Using temporary | | 2 | DERIVED | Y | eq_ref | PRIMARY | PRIMARY | 4 | db.X.pID | 1 | Distinct | | 2 | DERIVED | Z | ref | PRIMARY | PRIMARY | 4 | db.Y.gID | 2 | Using index; Distinct | +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ 7 rows in set (0.48 sec) The explain here looks pretty cryptic, and I don't know whether I should drop view and write a script to just insert everything in the view to a hard table. ( obviously, it will lose the flexibility of the view since the mapping changes quite frequently). Does anyone have any idea to how I can optimize my schema better?

  Read the article

• Where are the network boundaries in the Java Connector Architecture (JCA)?

  - by Laird Nelson

  I am writing a JCA resource adapter. I'm also, as I go, trying to fully understand the connection management portion of the JCA specification. As a thought experiment, pretend that the only client of this adapter will be a Swing Java Application Client located on a different machine. Also assume that the resource adapter will communicate with its "enterprise information system" (EIS) over the network as well. As I understand the JCA specification, the .rar file is deployed to the application server. The application server creates the .rar file's implementation of the ManagedConnectionFactory interface. It then asks it to produce a connection factory, which is the opaque object that is deployed to JNDI for the user to use to obtain a connection to the resource. (In the case of JDBC, the connection factory is a javax.sql.DataSource.) It is a requirement that the connection factory retain a reference to the application-server-supplied ConnectionManager, which, in turn, is required to be Serializable. This makes sense--in order for the connection factory to be stored in JNDI, it must be serializable, and in order for it to keep a reference to the ConnectionManager, the ConnectionManager must also be serializable. So fine, this little object graph gets installed in the application client's JNDI tree. This is where I start to get queasy. Is the ConnectionManager--the piece supplied by the application server that is supposed to handle connection management, sharing, pooling, etc.--wholly present on the client at this point? One of its jobs is to create ManagedConnection instances, and a ManagedConnection is not required to be Serializable, and the user connection handles it vends are also not required to be Serializable. That suggests to me that the whole connection pooling machinery is shipped wholesale to the application client and stuffed into its JNDI tree. Does this all mean that JCA interactions from the client side bypass the server-side componentry of the application server? Where are the network boundaries in the JCA API?

  Read the article

• Can i change the identity of the logged in user in ASP.net?

  - by Rising Star

  I have an ASP.net application I'm developing authentication for. I am using an existing cookie-based log on system to log users in to the system. The application runs as an anonymous account and then checks the cookie when the user wants to do something restricted. This is working fine. However, there is one caveat: I've been told that for each page that connects to our SQL server, I need to make it so that the user connects using an Active Directory account. because the system I'm using is cookie based, the user isn't logged in to Active Directory. Therefore, I use impersonation to connect to the server as a specific account. However, the powers that be here don't like impersonation; they say that it clutters up the code. I agree, but I've found no way around this. It seems that the only way that a user can be logged in to an ASP.net application is by either connecting with Internet Explorer from a machine where the user is logged in with their Active Directory account or by typing an Active Directory username and password. Neither of these two are workable in my application. I think it would be nice if I could make it so that when a user logs in and receives the cookie (which actually comes from a separate log on application, by the way), there could be some code run which tells the application to perform all network operations as the user's Active Directory account, just as if they had typed an Active Directory username and password. It seems like this ought to be possible somehow, but the solution evades me. How can I make this work?

  Read the article

• What might be causing this Rails method error?

  - by Trip

  My error: Notice the undefined method '-@' . This is for a sort by. All sorts on one page break, but all the sorts on other pages use the same helper and do not break. Does it allude to something obvious? Processing OrganizationsController#search (for ::1 at 2010-05-13 15:42:01) [GET] Parameters: {"action"=>"search", "controller"=>"organizations", "direction"=>"desc", "_"=>"1273779721464", "order_by"=>"published_at"} SQL (0.5ms) SHOW TABLES Organization Columns (2.2ms) SHOW FIELDS FROM `organizations` NoMethodError (undefined method `-@' for #<Array:0x2f88cc8>): app/controllers/organizations_controller.rb:190:in `search' sunspot (1.0.5) lib/sunspot/util.rb:84:in `call' sunspot (1.0.5) lib/sunspot/util.rb:84:in `instance_eval_or_call' sunspot (1.0.5) lib/sunspot/search.rb:200:in `build' sunspot (1.0.5) lib/sunspot/session.rb:45:in `new_search' sunspot (1.0.5) lib/sunspot/session.rb:53:in `search' sunspot (1.0.5) lib/sunspot/session_proxy/abstract_session_proxy.rb:11:in `search' sunspot (1.0.5) lib/sunspot.rb:323:in `search' app/controllers/organizations_controller.rb:183:in `search' haml (2.2.2) [v] rails/./lib/sass/plugin/rails.rb:19:in `process' lib/flash_session_cookie_middleware.rb:14:in `call' vendor/gems/hoptoad_notifier-2.2.2/lib/hoptoad_notifier/rack.rb:27:in `call' /usr/local/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' /usr/local/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /usr/local/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' /usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start' /usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start_thread' /usr/local/lib/ruby/1.8/webrick/server.rb:95:in `start' /usr/local/lib/ruby/1.8/webrick/server.rb:92:in `each' /usr/local/lib/ruby/1.8/webrick/server.rb:92:in `start' /usr/local/lib/ruby/1.8/webrick/server.rb:23:in `start' /usr/local/lib/ruby/1.8/webrick/server.rb:82:in `start' Rendered rescues/_trace (68.5ms) Rendered rescues/_request_and_response (0.6ms) Rendering rescues/layout (internal_server_error)

  Read the article

• Oracle 10.1 and 11.2 produce different XML using the same statement

  - by MindFyer

  I am migrating a database from Oracle 10.1 to 11.2 and I have the following problem. The statement SELECT '<?xml version="1.0" encoding="utf-8" ?>' || (Xml).getClobVal() AS XmlClob FROM ( SELECT XmlElement( "Element1", ( SELECT XmlAgg(tpx.Xml) FROM ( SELECT XmlElement("Element3",XmlForest('content' as Element4)) AS Xml FROM dual ) tpx ) AS "Element2" ) AS Xml FROM dual ) On the original 10.1 database produces XML like this... <?xml version="1.0" encoding="utf-8"?> <Element1> <Element2> <Element3> <ELEMENT4>content</ELEMENT4> </Element3> </Element2> </Element1> On the new 11.2 system it looks like this... <?xml version="1.0" encoding="utf-8"?> <Element1> <Element3> <ELEMENT4>content</ELEMENT4> </Element3> </Element1> Is there some environmental variable I am missing that tells Oracle how to format its XML. There are hundreds of thousands of lines of PL/SQL in the database; it would be a mammoth task to rewrite if it turned out they had changed they way Oracle formats XML between versions. Hopefully someone has come accross this before. Thanks

  Read the article

• Entity framework self referencing loop detected

  - by Lyd0n

  I have a strange error. I'm experimenting with a .NET 4.5 Web API, Entity Framework and MS SQL Server. I've already created the database and set up the correct primary and foreign keys and relationships. I've created a .edmx model and imported two tables: Employee and Department. A department can have many employees and this relationship exists. I created a new controller called EmployeeController using the scaffolding options to create an API controller with read/write actions using Entity Framework. In the wizard, selected Employee as the model and the correct entity for the data context. The method that is created looks like this: // GET api/Employee public IEnumerable<Employee> GetEmployees() { var employees = db.Employees.Include(e => e.Department); return employees.AsEnumerable(); } When I call my API via /api/Employee, I get this error: ...The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; ...System.InvalidOperationException","StackTrace":null,"InnerException":{"Message":"An error has occurred.","ExceptionMessage":"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.Employee_5D80AD978BC68A1D8BD675852F94E8B550F4CB150ADB8649E8998B7F95422552'. Path '[0].Department.Employees'.","ExceptionType":"Newtonsoft.Json.JsonSerializationException","StackTrace":" ... Why is it self referencing [0].Department.Employees? That doesn't make a whole lot of sense. I would expect this to happen if I had circular referencing in my database but this is a very simple example. What could be going wrong?

  Read the article

• (Rails) Creating multi-dimensional hashes/arrays from a data set...?

  - by humble_coder

  Hi All, I'm having a bit of an issue wrapping my head around something. I'm currently using a hacked version of Gruff in order to accommodate "Scatter Plots". That said, the data is entered in the form of: g.data("Person1",[12,32,34,55,23],[323,43,23,43,22]) ...where the first item is the ENTITY, the second item is X-COORDs, and the third item is Y-COORDs. I currently have a recordset of items from a table with the columns: POINT, VALUE, TIMESTAMP. Due to the "complex" calculations involved I must grab everything using a single query or risk way too much DB activity. That said, I have a list of items for which I need to dynamically collect all data from the recordset into a hash (or array of arrays) for the creation of the data items. I was thinking something like the following: @h={} e = Events.find_by_sql(my_query) e.each do |event| @h["#{event.Point}"][x] = event.timestamp @h["#{event.Point}"][y] = event.value end Obviously that's not the correct syntax, but that's where my brain is going. Could someone clean this up for me or suggest a more appropriate mechanism by which to accomplish this? Basically the main goal is to keep data for each pointname grouped (but remember the recordset has them all). Much appreciated. EDIT 1 g = Gruff::Scatter.new("600x350") g.title = self.name e = Event.find_by_sql(@sql) h ={} e.each do |event| h[event.Point.to_s] ||= {} h[event.Point.to_s].merge!({event.Timestamp.to_i,event.Value}) end h.each do |p| logger.info p[1].values.inspect g.data(p[0],p[1].keys,p[1].values) end g.write(@chart_file)

  Read the article

• NHibernate: What are child sessions and why and when should I use them?

  - by stefando

  In the comments for the ayende's blog about the auditing in NHibernate there is a mention about the need to use a child session:session.GetSession(EntityMode.Poco). As far as I understand it, it has something to do with the order of the SQL operation which session.Flush will emit. (For example: If I wanted to perform some delete operation in the pre-insert event but the session was already done with deleting operations, I would need some way to inject them in.) However I did not find documentation about this feature and behavior. Questions: Is my understanding of child sessions correct? How and in which scenarios should I use them? Are they documented somewhere? Could they be used for session "scoping"? (For example: I open the master session which will hold some data and then I create 2 child-sessions from the master one. I'd expect that the two child-scopes will be separated but the will share objects from the master session cache. Is this the case?) Are they first class citizens in NHibernate or are they just hack to support some edge-case scenarios? Thanks in advance for any info.

  Read the article

• AJAX filter MySQL results using checkboxes

  - by keepitnang

  I'm attempting to get to grips with displaying filterable MySQL data within a PHP page based on user checkbox selections. I have a database of domain names and the dates on which these will require renewal as per Nominet DAC information and I can get unfiltered data to display, but filtering results by domain extensions is proving tricky for me to accomplish. I should point out at this stage that I am a serious newcomer to many of the ideas I am trying to learn to work with here, so please be gentle. I have tried following some other articles on here also, but no dice. I have the following so far: HTML <input type="checkbox" class="extensions" name="extensions" value=".co.uk">.co.uk</input> <input type="checkbox" class="extensions" name="extensions" value=".org.uk">.org.uk</input> Script $('.extensions').live('click', function() { var all_boxes = $('.extensions'); var all_boxes_values = []; var i = 0; for (var i; i < all_boxes.length; i++) { if (all_boxes[i].checked) { all_boxes_values.push(all_boxes[i].value) } } var all_boxes_values_clean = all_boxes_values.join(", "); console.log(all_boxes_values_clean); $.get("sql-test.php", {q: all_boxes_values_clean}, function(result) { $("div#output").html(result); } )}); PHP $g = $_GET['q']; $extensionsql=""; $extension=1; if(isset($g)) { $extension=1; $param = "" . str_replace(",", "','", $_GET['q']) . ""; } And that's as far as I have gotten with my limited ability. What I would like to do next is search the column domainName for a string match and return the appropriate results to the user. Something to mimic something like the following but I'm not sure how to achieve it. Any help would be much appreciated: SELECT * FROM `refresh` WHERE `domainName` LIKE '%.co.uk%' AND renewalDate LIKE '%2012-06-30%' ORDER BY `domainName` ASC Thanks

  Read the article

• Invalid Argument javascript error only on certain computers

  - by Jen

  Getting an error whenever we click a particular button/link on our site. It is generating a javascript "Invalid Argument" error. I know in the other posts it is typically because it is a syntax error in the javascript however it only just seems to have started happening and it doesn't happen on all pcs. ie. in our client's environment if I remote onto their web server and view the uat website I get the javascript error. If I remote onto their sql server and view the uat website I don't get the javascript error. If it was a syntax error then I would always get the error wouldn't I? both browsers are the same version of IE6 (yeah I know...) :) I have tried deleting temporary internet files - including viewing the files and deleting them myself - but no joy. client uses citrix.. and they're all getting the error :( Any ideas would be appreciated - Thanks! :) Update - Sorry I haven't posted specific code as there is too much to post (and I'm not sure where the error is occurring). The "button" launches a new window which in turn opens up a couple of aspx pages and calls lots of javascript. So the window opens ok, and there's a function that gets called to resize the window - but before it calls the resizing of the window/content it throws the invalid argument error. Am busy trying to get alerts to trigger to see if I can see where it's falling over but so far no luck. Again not sure why this error doesn't occur when I use a particular PC (same browser version)

  Read the article

• Execute a block of database querys

  - by Nightmare

  I have the following task to complete: In my program a have a block of database querys or questions. I want to execute these questions and wait for the result of all questions or catch an error if one question fails! My Question object looks like this (simplified): public class DbQuestion(String sql) { [...] } [...] //The answer is just a holder for custom data... public void SetAnswer(DbAnswer answer) { //Store the answer in the question and fire a event to the listeners this.OnAnswered(EventArgs.Empty); } [...] public void SetError() { //Signal an Error in this query! this.OnError(EventArgs.Empty); } So every question fired to the database has a listener that waits for the parsed result. Now I want to fire some questions asynchronous to the database (max. 5 or so) and fire an event with the data from all questions or an error if only one question throws one! Which is the best or a good way to accomplish this task? Can I really execute more then one question parallel and stop all my work when one question throws an error? I think I need some inspiration on this... Just a note: I´m working with .NET framework 2.0

  Read the article

• Javascript nested functions not returning

  - by Achintha Samindika

  I'm building a phonehap application. I'm using an web sql and everything works fine till data retival. function getItemGroups(){ var items_groups = new Array(); var db = window.openDatabase("merbokDB", "1.0", "MerbokDB", 5232394); db.transaction( function(tx){ tx.executeSql('SELECT * FROM item_groups',[], function(tx,result){ if(result.rows.length > 0){ var len = result.rows.length; for (var i=0; i<len; i++){ items_groups.push(result.rows.item(i).item_group); } console.log(items_groups.join()); } } ,errorCB); }, errorCB); return items_groups; } var myproducts = getItemGroups(); My problem was when I run the code "myproducts" variable is blank. but the I can see console.log(items_groups.join()); following line printing the values in console. Is I'm wrong in the way I returning?

  Read the article

• What is the best way to do scoped finds based on access control rules in Rails?

  - by Rafael Szuminski

  Hi I need to find an elegant solution to scoped finds based on access control rules. Essentially I have the following setup: Users Customers AccessControl - Defines which user has access to another users data Users need to be able to access not just their own customers but also shared customers of other users. Obviously something like a simple association will not work: has_many :customers and neither will this: has_many :customers, :conditions => 'user_id in (1,2,3,4,5)' because the association uses with_scope and the added condition is an AND condition not an OR condition. I also tried overriding the find and method_missing methods with the association extension like this: has_many :customers do def find(*args) #get the user_id and retrieve access conditions based on the id #do a find based on the access conditions and passed args end def method_missing(*args) #get the user_id and retrieve access conditions based on the id #do a find based on the access conditions and passed args end end but the issue is that I don't have access to the user object / parent object inside the extension methods and it just does not work as planned. I also tried default_scope but as posted here before you can't pass a block to a default scope. Anyhow, I know that data segmentation and data access controls have been done before using rails and am wondering if somebody found an elegant way to do it. UPDATE: The AccessControl table has the following layout user_id shared_user_id The customer table has this structure: id account_id user_id first_name last_name Assuming the the following data would be in the AccessControl table: 1 1 1 3 1 4 2 2 2 13 and so on... And the account_id for user 1 is 13 I need to be able to retrieve customers that can be best described with the following sql statement: select * from customers where (account_id = 13 and user_id = null) or (user_id in (1,3,4))

  Read the article

• What's best choice career-wise, to know a little about a lot or a lot about a little?

  - by nimo

  I work as a developer at a rather small company and we are providing a web application that is used by a big base of customers. Because we are so small everyone have to be able to do a lot of different tasks. It ranges from advanced support, developing the product (programming: c/c++, c#, php, sql, javascript, html, css), handle network configuration and network related issues and even sometimes go on sales meetings with potential customers. My concern is that I don't really specialize in any specific area. I know and learn little about a lot. I have graduated from school two years ago and this is my first real employment and when I look at other positions out there they always require so and so many years of experience in a specific area (for example 5 years of C#). For me to get that kind of specialized experience will be really hard at my current job. My question for you is what is, in your opinion, best choice career-wise, to know a little about a lot or a lot about a little? What path did you take? pros and cons that comes with that choice.

  Read the article

• Best practices for (over)using Azure queues

  - by John

  Hi, I'm in the early phases of designing an Azure-based application. One of the things that attracts me to Azure is the scalability, given the variability of the demand I'm likely to expect. As such I'm trying to keep things loosely coupled so I can add instances when I need to. The recommendations I've seen for architecting an application for Azure include keeping web role logic to a minimum, and having processing done in worker roles, using queues to communicate and some sort of back-end store like SQL Azure or Azure Tables. This seems like a good idea to me as I can scale up either or both parts of the application without any issue. However I'm curious if there are any best practices (or if anyone has any experiences) for when it's best to just have the web role talk directly to the data store vs. sending data by the queue? I'm thinking of the case where I have a simple insert to do from the web role - while I could set this up as a message, send it on the queue, and have a worker role pick it up and do the insert, it seems like a lot of double-handling. However I also appreciate that it may be the case that this is better in the long run, in case the web role gets overwhelmed or more complex logic ends up being required for the insert. I realise this might be a case where the answer is "it depends entirely on the situation, check your perf metrics" - but if anyone has any thoughts I'd be very appreciative! Thanks John

  Read the article

• Two entities with @ManyToOne joins the same table

  - by Ivan Yatskevich

  I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

  Read the article

• WPF C# Client/Server announcement system

  - by manemawanna

  I'm currently in the process of creating an announcement system at my place of work. The role of this system will be to replace all users email due to people misusing it and generally abusing the facility. The system will consist of: Web Portal: Will allow staff to enter any important announcements (this will be restricted via AD). SQL Server 2k5 DB: Will hold the announcements along with records of staff members and if they've read the announcements etc. Front End: Created in WPF & C# which is nearly complete, it will display the announcements to the users. Web Page: Client will contact every so often, which will return an xml file for the client to read. However my boss has now shifted the goal posts and would like the announcements to appear to the user once they are written to the database, rather than waiting on the client to contact the webpage. So now I'm a bit unsure as to how to go about this. I have one idea where I would create a small server application to monitor for new announcements then contact the clients to inform them to approach the website for the information they need. But I'm just looking to see if theres a better or more efficient way to do this or if someone else has a more appropriate idea or suggestion.

  Read the article

• Call Oracle package function using Odbc from C#

  - by Paolo Tedesco

  I have a function defined inside an Oracle package: CREATE OR REPLACE PACKAGE BODY TESTUSER.TESTPKG as FUNCTION testfunc(n IN NUMBER) RETURN NUMBER as begin return n + 1; end testfunc; end testpkg; / How can I call it from C# using Odbc? I tried the following: using System; using System.Data; using System.Data.Odbc; class Program { static void Main(string[] args) { using (OdbcConnection connection = new OdbcConnection("DSN=testdb;UID=testuser;PWD=testpwd")) { connection.Open(); OdbcCommand command = new OdbcCommand("TESTUSER.TESTPKG.testfunc", connection); command.CommandType = System.Data.CommandType.StoredProcedure; command.Parameters.Add("ret", OdbcType.Int).Direction = ParameterDirection.ReturnValue; command.Parameters.Add("n", OdbcType.Int).Direction = ParameterDirection.Input; command.Parameters["n"].Value = 42; command.ExecuteNonQuery(); Console.WriteLine(command.Parameters["ret"].Value); } } } But I get an exception saying "Invalid SQL Statement". What am I doing wrong?

  Read the article

• Need a refresher course on property access...

  - by Code Sherpa

  Hi. I need help with accessing class properties within a given class. For example, take the below class: public partial class Account { private Profile _profile; private Email _email; private HostInfo _hostInfo; public Profile Profile { get { return _profile; } set { _profile = value; } } public Email Email { get { return _email; } set { _email = value; } } public HostInfo HostInfo { get { return _hostInfo; } set { _hostInfo = value; } } In the class "Account" exists a bunch of class properties such as Email or Profile. Now, when I want to access those properties at run-time, I do something like this (for Email): _accountRepository = ObjectFactory.GetInstance<IAccountRepository>(); string username = Cryptography.Decrypt(_webContext.UserNameToVerify, "verify"); Account account = _accountRepository.GetAccountByUserName(username); if(account != null) { account.Email.IsConfirmed = true; But, I get "Object reference not set..." for account.Email... Why is that? How do I access Account such that account.Email, account.Profile, and so on returns the correct data for a given AccountId or UserName. Here is a method that returns Account: public Account GetAccountByUserName(string userName) { Account account = null; using (MyDataContext dc = _conn.GetContext()) { try { account = (from a in dc.Accounts where a.UserName == userName select a).FirstOrDefault(); } catch { //oops } } return account; } The above works but when I try: account = (from a in dc.Accounts join em in dc.Emails on a.AccountId equals em.AccountId join p in dc.Profiles on em.AccountId equals p.AccountId where a.UserName == userName select a).FirstOrDefault(); I am still getting object reference exceptions for my Email and Profile properties. Is this simply a SQL problem or is there something else I need to be doing to be able to fully access all the properties within my Account class? Thanks!

  Read the article

• How to specify multiple values in where with AR query interface in rails3

  - by wkhatch

  Per section 2.2 of rails guide on Active Record query interface here: which seems to indicate that I can pass a string specifying the condition(s), then an array of values that should be substituted at some point while the arel is being built. So I've got a statement that generates my conditions string, which can be a varying number of attributes chained together with either AND or OR between them, and I pass in an array as the second arg to the where method, and I get: ActiveRecord::PreparedStatementInvalid: wrong number of bind variables (1 for 5) which leads me to believe I'm doing this incorrectly. However, I'm not finding anything on how to do it correctly. To restate the problem another way, I need to pass in a string to the where method such as "table.attribute = ? AND table.attribute1 = ? OR table.attribute1 = ?" with an unknown number of these conditions anded or ored together, and then pass something, what I thought would be an array as the second argument that would be used to substitute the values in the first argument conditions string. Is this the correct approach, or, I'm just missing some other huge concept somewhere and I'm coming at this all wrong? I'd think that somehow, this has to be possible, short of just generating a raw sql string.

  Read the article

• Change HTML image into a Button for partial refresh of page

  - by user990951

  I am new to webpage design and MVC. I have a aspx page and I have a html image. I want to change this image and make it clickable so that it will refresh only the bottom half of the page when clicked. I setup my image so that the source of the image is updated by the controller. By using the following src="<%=ViewData["BookImg"] %>" So that the whole story is clear. When a person clicks on the image of the book, it displays on the bottom half of the page information about that book pulled from a sql database. I am thinking that I would need to look into getting ajax implemented so that I can do partial page update. But the question is how do I change that HTML image into a button. Thanks in advance. ---updating per the answer chosen but still having problems--- home.aspx <% Html.RenderPartial("HomePartialView"); %> <img id = "Book_Img" src="<%=ViewData["BookImg"] %>" alt = "click Me" class="imgClick"/> <script src="../../Scripts/jquery-1.5.1.js" type="text/javascript"> $(document).ready(function(){ $(".imgClick").click(function () { $("HomePartialView").load("../../Controllers/HomeController/PartialViewBook"); }); }); </script> ---Controller public ActionResult PartialViewBook() { ViewData[imageBookPressd] = "hello world"; return View("HomePartialView"); }

  Read the article

< Previous Page | 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128  | Next Page >