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  • refactor LINQ TO SQL custom properties that instantiate datacontext

    - by Thiago Silva
    I am working on an existing ASP.NET MVC app that started small and has grown with time to require a good re-architecture and refactoring. One thing that I am struggling with is that we've got partial classes of the L2S entities so we could add some extra properties, but these props create a new data context and query the DB for a subset of data. This would be the equivalent to doing the following in SQL, which is not a very good way to write this query as oppsed to joins: SELECT tbl1.stuff, (SELECT nestedValue FROM tbl2 WHERE tbl2.Foo = tbl1.Bar), tbl1.moreStuff FROM tbl1 so in short here's what we've got in some of our partial entity classes: public partial class Ticket { public StatusUpdate LastStatusUpdate { get { //this static method call returns a new DataContext but needs to be refactored var ctx = OurDataContext.GetContext(); var su = Compiled_Query_GetLastUpdate(ctx, this.TicketId); return su; } } } We've got some functions that create a compiled query, but the issue is that we also have some DataLoadOptions defined in the DataContext, and because we instantiate a new datacontext for getting these nested property, we get an exception "Compiled Queries across DataContexts with different LoadOptions not supported" . The first DataContext is coming from a DataContextFactory that we implemented with the refactorings, but this second one is just hanging off the entity property getter. We're implementing the Repository pattern in the refactoring process, so we must stop doing stuff like the above. Does anyone know of a good way to address this issue?

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  • Problem with interface implementation in partial classes.

    - by Bas
    I have a question regarding a problem with L2S, Autogenerated DataContext and the use of Partial Classes. I have abstracted my datacontext and for every table I use, I'm implementing a class with an interface. In the code below you can see I have the Interface and two partial classes. The first class is just there to make sure the class in the auto-generated datacontext inherets Interface. The other autogenerated class makes sure the method from Interface is implemented. namespace PartialProject.objects { public interface Interface { Interface Instance { get; } } //To make sure the autogenerated code inherits Interface public partial class Class : Interface { } //This is autogenerated public partial class Class { public Class Instance { get { return this.Instance; } } } } Now my problem is that the method implemented in the autogenerated class gives the following error: - Property 'Instance' cannot implement property from interface 'PartialProject.objects.Interface'. Type should be 'PartialProjects.objects.Interface'. <- Any idea how this error can be resolved? Keep in mind that I can't edit anything in the autogenerated code. Thanks in advance!

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  • SQLce DAL Linq to Sql or EntityFramework

    - by bretddog
    Hi, I'm learning databases, using SqlCe, and need business object to database mapping. Currently I try to decide if to use Linq to Sql, or EntityFramework. (I understand a bit L2S, but haven't familiarized with EF yet) The program will only be debeloped and used by myself, so I have good control of the priorities: I don't need to consider potential change of database type or data storage type, as I'm quite certain SQLce will stay sufficient. I DO expect continued development and changes to the data scheme while the program is in active use; change business object properties (Hence database columns), and possibly overall table scheme. So old data must be transported to new scheme. I also want to keep a decent degree of layer separation DAL/BLL, although this may not be necessary, it is good for me to learn these principles. My question is: With these priorities, would I have any benefit by choosing either Linq2Sql vs. EntityFramwork? (and please explain why) Btw, the project involves very simple table scheme with only 4-5 tables and very simple relations. Thanks!

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  • Are ternary operators not valid for linq-to-sql queries?

    - by KallDrexx
    I am trying to display a nullable date time in my JSON response. In my MVC Controller I am running the following query: var requests = (from r in _context.TestRequests where r.scheduled_time == null && r.TestRequestRuns.Count > 0 select new { id = r.id, name = r.name, start = DateAndTimeDisplayString(r.TestRequestRuns.First().start_dt), end = r.TestRequestRuns.First().end_dt.HasValue ? DateAndTimeDisplayString(r.TestRequestRuns.First().end_dt.Value) : string.Empty }); When I run requests.ToArray() I get the following exception: Could not translate expression ' Table(TestRequest) .Where(r => ((r.scheduled_time == null) AndAlso (r.TestRequestRuns.Count > 0))) .Select(r => new <>f__AnonymousType18`4(id = r.id, name = r.name, start = value(QAWebTools.Controllers.TestRequestsController). DateAndTimeDisplayString(r.TestRequestRuns.First().start_dt), end = IIF(r.TestRequestRuns.First().end_dt.HasValue, value(QAWebTools.Controllers.TestRequestsController). DateAndTimeDisplayString(r.TestRequestRuns.First().end_dt.Value), Invoke(value(System.Func`1[System.String])))))' into SQL and could not treat it as a local expression. If I comment out the end = line, everything seems to run correctly, so it doesn't seem to be the use of my local DateAndTimeDisplayString method, so the only thing I can think of is Linq to Sql doesn't like Ternary operators? I think I've used ternary operators before, but I can't remember if I did it in this code base or another code base (that uses EF4 instead of L2S). Is this true, or am I missing some other issue?

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  • LINQ to SQL: NOTing a prebuilt expression

    - by ck
    I'm building a library of functions for one of my core L2S classes, all of which return a bool to allow checking for certain situations. Example: Expression<Func<Account, bool>> IsSomethingX = a => a.AccountSupplementary != null && a.AccountSupplementary.SomethingXFlag != null && a.AccountSupplementary.SomethingXFlag.Value; Now to query where this is not true, I CAN'T do this: var myAccounts= context.Accounts .Where(!IsSomethingX); // does not compile However, using the syntax from the PredicateBuilder class, I've come up with this: public static IQueryable<T> WhereNot<T>(this IQueryable<T> items, Expression<Func<T, bool>> expr1) { var invokedExpr = Expression.Invoke(expr1, expr1.Parameters.Cast<Expression>()); return items.Where(Expression.Lambda<Func<T, bool>> (Expression.Not(invokedExpr), expr1.Parameters)); } var myAccounts= context.Accounts .WhereNot(IsSomethingX); // does compile which actually produces the correct SQL. Does this look like a good solution, and is there anything I need to be aware of that might cause me problems in future?

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  • LINQ To SQL Dynamic Select

    - by mcass20
    Can someone show me how to indicate which columns I would like returned at run-time from a LINQ To SQL statement? I am allowing the user to select items in a checkboxlist representing the columns they would like displayed in a gridview that is bound to the results of a L2S query. I am able to dynamically generate the WHERE clause but am unable to do the same with the SELECT piece. Here is a sample: var query = from log in context.Logs select log; query = query.Where(Log => Log.Timestamp > CustomReport.ReportDateStart); query = query.Where(Log => Log.Timestamp < CustomReport.ReportDateEnd); query = query.Where(Log => Log.ProcessName == CustomReport.ProcessName); foreach (Pair filter in CustomReport.ExtColsToFilter) { sExtFilters = "<key>" + filter.First + "</key><value>" + filter.Second + "</value>"; query = query.Where(Log => Log.FormattedMessage.Contains(sExtFilters)); }

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  • LINQ to SQL: To Attach or Not To Attach

    - by bradhe
    So I'm have a really hard time figuring out when I should be attaching to an object and when I shouldn't be attaching to an object. First thing's first, here is a small diagram of my (very simplified) object model. Edit: Okay, apparently I'm not allowed to post images...here you go: http://i.imgur.com/2ROFI.png In my DAL I create a new DataContext every time I do a data-related operation. Say, for instance, I want to save a new user. In my business layer I create a new user. var user = new User(); user.FirstName = "Bob"; user.LastName = "Smith"; user.Username = "bob.smith"; user.Password = StringUtilities.EncodePassword("MyPassword123"); user.Organization = someOrganization; // Assume that someOrganization was loaded and it's data context has been garbage collected. Now I want to go save this user. var userRepository = new RepositoryFactory.GetRepository<UserRepository>(); userRepository.Save(user); Neato! Here is my save logic: public void Save(User user) { if (!DataContext.Users.Contains(user)) { user.Id = Guid.NewGuid(); user.CreatedDate = DateTime.Now; user.Disabled = false; //DataContext.Organizations.Attach(user.Organization); DataContext.Users.InsertOnSubmit(user); } else { DataContext.Users.Attach(user); } DataContext.SubmitChanges(); // Finished here as well. user.Detach(); } So, here we are. You'll notice that I comment out the bit where the DataContext attachs to the organization. If I attach to the organization I get the following exception: NotSupportedException: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported. Hmm, that doesn't work. Let me try it without attaching (i.e. comment out that line about attaching to the organization). DuplicateKeyException: Cannot add an entity with a key that is already in use. WHAAAAT? I can only assume this is trying to insert a new organization which is obviously false. So, what's the deal guys? What should I do? What is the proper approach? It seems like L2S makes this quite a bit harder than it should be...

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  • Having trouble doing an Update with a Linq to Sql object

    - by Pure.Krome
    Hi folks, i've got a simple linq to sql object. I grab it from the database and change a field then save. No rows have been updated. :( When I check the full Sql code that is sent over the wire, I notice that it does an update to the row, not via the primary key but on all the fields via the where clause. Is this normal? I would have thought that it would be easy to update the field(s) with the where clause linking on the Primary Key, instead of where'ing (is that a word :P) on each field. here's the code... using (MyDatabase db = new MyDatabase()) { var boardPost = (from bp in db.BoardPosts where bp.BoardPostId == boardPostId select bp).SingleOrDefault(); if (boardPost != null && boardPost.BoardPostId > 0) { boardPost.ListId = listId; // This changes the value from 0 to 'x' db.SubmitChanges(); } } and here's some sample sql.. exec sp_executesql N'UPDATE [dbo].[BoardPost] SET [ListId] = @p6 WHERE ([BoardPostId] = @p0) AND .... <snip the other fields>',N'@p0 int,@p1 int,@p2 nvarchar(9),@p3 nvarchar(10),@p4 int,@p5 datetime,@p6 int',@p0=1276,@p1=212787,@p2=N'ttreterte',@p3=N'ttreterte3',@p4=1,@p5='2009-09-25 12:32:12.7200000',@p6=72 Now, i know there's a datetime field in this update .. and when i checked the DB it's value was/is '2009-09-25 12:32:12.720' (less zero's, than above) .. so i'm not sure if that is messing up the where clause condition... but still! should it do a where clause on the PK's .. if anything .. for speed! Yes / no ? UPDATE After reading nitzmahone's reply, I then tried playing around with the optimistic concurrency on some values, and it still didn't work :( So then I started some new stuff ... with the optimistic concurrency happening, it includes a where clause on the field it's trying to update. When that happens, it doesn't work. so.. in the above sql, the where clause looks like this ... WHERE ([BoardPostId] = @p0) AND ([ListId] IS NULL) AND ... <rest snipped>) This doesn't sound right! the value in the DB is null, before i do the update. but when i add the ListId value to the where clause (or more to the point, when L2S add's it because of the optomistic concurrecy), it fails to find/match the row. wtf?

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  • How to reflect over T to build an expression tree for a query?

    - by Alex
    Hi all, I'm trying to build a generic class to work with entities from EF. This class talks to repositories, but it's this class that creates the expressions sent to the repositories. Anyway, I'm just trying to implement one virtual method that will act as a base for common querying. Specifically, it will accept a an int and it only needs to perform a query over the primary key of the entity in question. I've been screwing around with it and I've built a reflection which may or may not work. I say that because I get a NotSupportedException with a message of LINQ to Entities does not recognize the method 'System.Object GetValue(System.Object, System.Object[])' method, and this method cannot be translated into a store expression. So then I tried another approach and it produced the same exception but with the error of The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities. I know it's because EF will not parse the expression the way L2S will. Anyway, I'm hopping someone with a bit more experience can point me into the right direction on this. I'm posting the entire class with both attempts I've made. public class Provider<T> where T : class { protected readonly Repository<T> Repository = null; private readonly string TEntityName = typeof(T).Name; [Inject] public Provider( Repository<T> Repository) { this.Repository = Repository; } public virtual void Add( T TEntity) { this.Repository.Insert(TEntity); } public virtual T Get( int PrimaryKey) { // The LINQ expression node type 'ArrayIndex' is not supported in // LINQ to Entities. return this.Repository.Select( t => (((int)(t as EntityObject).EntityKey.EntityKeyValues[0].Value) == PrimaryKey)).Single(); // LINQ to Entities does not recognize the method // 'System.Object GetValue(System.Object, System.Object[])' method, // and this method cannot be translated into a store expression. return this.Repository.Select( t => (((int)t.GetType().GetProperties().Single( p => (p.Name == (this.TEntityName + "Id"))).GetValue(t, null)) == PrimaryKey)).Single(); } public virtual IList<T> GetAll() { return this.Repository.Select().ToList(); } protected virtual void Save() { this.Repository.Update(); } }

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  • CodePlex Daily Summary for Thursday, March 11, 2010

    CodePlex Daily Summary for Thursday, March 11, 2010New ProjectsASP.NET Wiki Control: This ASP.NET user control allows you to embed a very useful wiki directly into your already existing ASP.NET website taking advantage of the popula...BabyLog: Log baby daily activity.buddyHome: buddyHome is a project that can make your home smarter. as good as your buddy. Cloud Community: Cloud Community makes it easier for organizations to have a simple to use community platform. Our mission is to create an easy to use community pl...Community Connectors for Microsoft CRM 4.0: Community Connectors for Microsoft CRM 4.0 allows Microsoft CRM 4.0 customers and partners to monitor and analyze customers’ interaction from their...Console Highlighter: Hightlights Microsoft Windows Command prompt (cmd.exe) by outputting ANSI VT100 Control sequences to color the output. These sequences are not hand...Cornell Store: This is IN NO WAY officially affiliated or related to the Cornell University store. Instead, this is a project that I am doing for a class. Ther...DevUtilities: This project is for creating some utility tools, and they will be useful during the development.DotNetNuke® Skin Maple: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by DyNNamite.co.uk. The package includes 4 color variations and sev...HRNet: HRNetIIS Web Site Monitoring: A software for monitor a particular web site on IIS, even if its IP is sharing between different web site.Iowa Code Camp: The source code for the Iowa Code Camp website.Leonidas: Leonidas is a virtual tutorLunch 'n Learn: The Lunch 'n Learn web application is an open source ASP.NET MVC application that allows you to setup lunch 'n learn presentations for your team, c...MNT Cryptography: A very simple cryptography classMooiNooi MVC2LINQ2SQL Web Databinder: mvc2linq2sql is a databinder for ASP.NET MVC that make able developer to clean bind object from HTML FORMS to Linq entities. Even 1 to N relations ...MoqBot: MoqBot is an auto mocking library for Moq and Ninject.mtExperience1: hoiMvcPager: MvcPager is a free paging component for ASP.NET MVC web application, it exposes a series of extension methods for using in ASP.NET MVC applications...OCal: OCal is based on object calisthenics to identify code smellsPex Custom Arithmetic Solver: Pex Custom Arithmetic Solver contains a collection of meta-heuristic search algorithms. The goal is to improve Pex's code coverage for code involvi...SetControls: Расширеные контролы для ASP.NET приложений. Полная информация ближе к релизу...shadowrage1597: CTC 195 Game Design classSharePoint Team-Mailer: A SharePoint 2007 solution that defines a generic CustomList for sending e-mails to SharePoint Groups.Sql Share: SQL Share is a collaboration tool used within the science to allow database engineers to work tightly with domain scientists.TechCalendar: Tech Events Calendar ASP.NET project.ZLYScript: A very simple script language compiler.New ReleasesALGLIB: ALGLIB 2.4.0: New ALGLIB release contains: improved versions of several linear algebra algorithms: QR decomposition, matrix inversion, condition number estimatio...AmiBroker Plug-Ins with C#: AmiBroker Plug-Ins v0.0.2: Source codes and a binaryAppFabric Caching UI Admin Tool: AppFabric Caching Beta 2 UI Admin Tool: System Requirements:.NET 4.0 RC AppFabric Caching Beta2 Test On:Win 7 (64x)Autodocs - WCF REST Automatic API Documentation Generator: Autodocs.ServiceModel.Web: This archive contains the reference DLL, instructions and license.Compact Plugs & Compact Injection: Compact Injection and Compact Plugs 1.1 Beta: First release of Compact Plugs (CP). The solution includes a simple example project of CP, called "TestCompactPlugs1". Also some fixes where made ...Console Highlighter: Console Highlighter 0.9 (preview release): Preliminary release.Encrypted Notes: Encrypted Notes 1.3: This is the latest version of Encrypted Notes (1.3). It has an installer - it will create a directory 'CPascoe' in My Documents. The last one was ...Family Tree Analyzer: Version 1.0.2: Family Tree Analyzer Version 1.0.2 This early beta version implements loading a gedcom file and displaying some basic reports. These reports inclu...FRC1103 - FRC Dashboard viewer: 2010 Documentation v0.1: This is my current version of the control system documentation for 2010. It isn't complete, but it has the information required for a custom dashbo...jQuery.cssLess: jQuery.cssLess 0.5 (Even less release): NEW - support for nested special CSS classes (like :hover) MAIN RELEASE This release, code "Even less", is the one that will interpret cssLess wit...MooiNooi MVC2LINQ2SQL Web Databinder: MooiNooi MVC2LINQ2SQL DataBinder: I didn't try this... I just took it off from my project. Please, tell me any problem implementing in your own development and I'll be pleased to h...MvcPager: MvcPager 1.2 for ASP.NET MVC 1.0: MvcPager 1.2 for ASP.NET MVC 1.0Mytrip.Mvc: Mytrip 1.0 preview 1: Article Manager Blog Manager L2S Membership(.NET Framework 3.5) EF Membership(.NET Framework 4) User Manager File Manager Localization Captcha ...NodeXL: Network Overview, Discovery and Exploration for Excel: NodeXL Excel 2007 Template, version 1.0.1.117: The NodeXL Excel 2007 template displays a network graph using edge and vertex lists stored in an Excel 2007 workbook. What's NewThis version adds ...Pex Custom Arithmetic Solver: PexCustomArithmeticSolver: This is the alpha release containing the Alternating Variable Method and Evolution Strategies to try and solve constraints over floating point vari...Scrum Sprint Monitor: v1.0.0.44877: What is new in this release? Major performance increase in animations (up to 50 fps from 2 fps) by replacing DropShadow effect with png bitmaps; ...sELedit: sELedit v1.0b: + Added support for empty strings / wstrings + Fixed: critical bug in configuration files (list 53)sPWadmin: pwAdmin v0.9_nightly: + Fixed: XML editor can now open and save character templates + Added: PWI item name database + Added: Plugin SupportTechCalendar: Events Calendar v.1.0: Initial release.The Silverlight Hyper Video Player [http://slhvp.com]: Beta 2: Beta 2.0 Some fixes from Beta 1, and a couple small enhancements. Intensive testing continues, and I will continue to update the code at least ever...ThreadSafe.Caching: 2010.03.10.1: Updates to the scavanging behaviour since last release. Scavenging will now occur every 30 seconds by default and all objects in the cache will be ...VCC: Latest build, v2.1.30310.0: Automatic drop of latest buildVisual Studio DSite: Email Sender (C++): The same Email Sender program that I but made in visual c plus plus 2008 instead of visual basic 2008.Web Forms MVP: Web Forms MVP CTP7: The release can be considered stable, and is in use behind several high traffic, public websites. It has been marked as a CTP release as it is not ...White Tiger: 0.0.3.1: Now you can load or create files with whatever root element you want *check f or sets file permisionsMost Popular ProjectsMetaSharpWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesASP.NET Ajax LibraryMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsN2 CMSFasterflect - A Fast and Simple Reflection APIjQuery Library for SharePoint Web ServicesBlogEngine.NETFarseer Physics Enginepatterns & practices – Enterprise LibraryCaliburn: An Application Framework for WPF and Silverlight

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  • Implementing a generic repository for WCF data services

    - by cibrax
    The repository implementation I am going to discuss here is not exactly what someone would call repository in terms of DDD, but it is an abstraction layer that becomes handy at the moment of unit testing the code around this repository. In other words, you can easily create a mock to replace the real repository implementation. The WCF Data Services update for .NET 3.5 introduced a nice feature to support two way data bindings, which is very helpful for developing WPF or Silverlight based application but also for implementing the repository I am going to talk about. As part of this feature, the WCF Data Services Client library introduced a new collection DataServiceCollection<T> that implements INotifyPropertyChanged to notify the data context (DataServiceContext) about any change in the association links. This means that it is not longer necessary to manually set or remove the links in the data context when an item is added or removed from a collection. Before having this new collection, you basically used the following code to add a new item to a collection. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; var context = new OrderContext(); context.AddToOrders(order); context.AddToOrderItems(item); context.SetLink(item, "Order", order); context.SaveChanges(); Now, thanks to this new collection, everything is much simpler and similar to what you have in other ORMs like Entity Framework or L2S. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; order.Items.Add(item); var context = new OrderContext(); context.AddToOrders(order); context.SaveChanges(); In order to use this new feature, you first need to enable V2 in the data service, and then use some specific arguments in the datasvcutil tool (You can find more information about this new feature and how to use it in this post). DataSvcUtil /uri:"http://localhost:3655/MyDataService.svc/" /out:Reference.cs /dataservicecollection /version:2.0 Once you use those two arguments, the generated proxy classes will use DataServiceCollection<T> rather than a simple ObjectCollection<T>, which was the default collection in V1. There are some aspects that you need to know to use this feature correctly. 1. All the entities retrieved directly from the data context with a query track the changes and report those to the data context automatically. 2. A entity created with “new” does not track any change in the properties or associations. In order to enable change tracking in this entity, you need to do the following trick. public Order CreateOrder() {   var collection = new DataServiceCollection<Order>(this.context);   var order = new Order();   collection.Add(order);   return order; } You basically need to create a collection, and add the entity to that collection with the “Add” method to enable change tracking on that entity. 3. If you need to attach an existing entity (For example, if you created the entity with the “new” operator rather than retrieving it from the data context with a query) to a data context for tracking changes, you can use the “Load” method in the DataServiceCollection. var order = new Order {   Id = 1 }; var collection = new DataServiceCollection<Order>(this.context); collection.Load(order); In this case, the order with Id = 1 must exist on the data source exposed by the Data service. Otherwise, you will get an error because the entity did not exist. These cool extensions methods discussed by Stuart Leeks in this post to replace all the magic strings in the “Expand” operation with Expression Trees represent another feature I am going to use to implement this generic repository. Thanks to these extension methods, you could replace the following query with magic strings by a piece of code that only uses expressions. Magic strings, var customers = dataContext.Customers .Expand("Orders")         .Expand("Orders/Items") Expressions, var customers = dataContext.Customers .Expand(c => c.Orders.SubExpand(o => o.Items)) That query basically returns all the customers with their orders and order items. Ok, now that we have the automatic change tracking support and the expression support for explicitly loading entity associations, we are ready to create the repository. The interface for this repository looks like this,public interface IRepository { T Create<T>() where T : new(); void Update<T>(T entity); void Delete<T>(T entity); IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties); IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties); void Attach<T>(T entity); void SaveChanges(); } The Retrieve and RetrieveAll methods are used to execute queries against the data service context. While both methods receive an array of expressions to load associations explicitly, only the Retrieve method receives a predicate representing the “where” clause. The following code represents the final implementation of this repository.public class DataServiceRepository: IRepository { ResourceRepositoryContext context; public DataServiceRepository() : this (new DataServiceContext()) { } public DataServiceRepository(DataServiceContext context) { this.context = context; } private static string ResolveEntitySet(Type type) { var entitySetAttribute = (EntitySetAttribute)type.GetCustomAttributes(typeof(EntitySetAttribute), true).FirstOrDefault(); if (entitySetAttribute != null) return entitySetAttribute.EntitySet; return null; } public T Create<T>() where T : new() { var collection = new DataServiceCollection<T>(this.context); var entity = new T(); collection.Add(entity); return entity; } public void Update<T>(T entity) { this.context.UpdateObject(entity); } public void Delete<T>(T entity) { this.context.DeleteObject(entity); } public void Attach<T>(T entity) { var collection = new DataServiceCollection<T>(this.context); collection.Load(entity); } public IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query.Where(predicate); } public IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query; } public void SaveChanges() { this.context.SaveChanges(SaveChangesOptions.Batch); } } For instance, you can use the following code to retrieve customers with First name equal to “John”, and all their orders in a single call. repository.Retrieve<Customer>(    c => c.FirstName == “John”, //Where    c => c.Orders.SubExpand(o => o.Items)); In case, you want to have some pre-defined queries that you are going to use across several places, you can put them in an specific class. public static class CustomerQueries {   public static Expression<Func<Customer, bool>> LastNameEqualsTo(string lastName)   {     return c => c.LastName == lastName;   } } And then, use it with the repository. repository.Retrieve<Customer>(    CustomerQueries.LastNameEqualsTo("foo"),    c => c.Orders.SubExpand(o => o.Items));

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  • Linq 2 SQL using base class and WCF

    - by Gena Verdel
    Hi all. I have the following problem: I'm using L2S for generating entity classes. All these classes share the same property ID which is autonumber. So I figured to put this property to base class and extend all entity classes from the base one. In order to be able to read the value I'm using the override modifier on this property in each and every entity class. Up to now it's live and kicking. Then I decided to introduce another tier - services using WCF approach. I've modified the Serialization mode to Unidirectional (and added the IsReference=true attribute to enable two directions), also added [DataContract] attribute to the BaseObject class. WCF is able to transport the whole object but one property , which is ID. Applying [DataMember] attribute on ID property at the base class resulted in nothing. Am I missing something? Is what I'm trying to achieve possible at all? [DataContract()] abstract public class BaseObject : IIccObject public virtual long ID { get; set; } [Table(Name="dbo.Blocks")] [DataContract(IsReference=true)] public partial class Block : INotifyPropertyChanging, INotifyPropertyChanged { private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty); private long _ID; private int _StatusID; private string _Name; private bool _IsWithControlPoints; private long _DivisionID; private string _SHAPE; private EntitySet<BlockByWorkstation> _BlockByWorkstations; private EntitySet<PlanningPointAppropriation> _PlanningPointAppropriations; private EntitySet<Neighbor> _Neighbors; private EntitySet<Neighbor> _Neighbors1; private EntitySet<Task> _Tasks; private EntitySet<PlanningPointByBlock> _PlanningPointByBlocks; private EntityRef<Division> _Division; private bool serializing; #region Extensibility Method Definitions partial void OnLoaded(); partial void OnValidate(System.Data.Linq.ChangeAction action); partial void OnCreated(); partial void OnIDChanging(long value); partial void OnIDChanged(); partial void OnStatusIDChanging(int value); partial void OnStatusIDChanged(); partial void OnNameChanging(string value); partial void OnNameChanged(); partial void OnIsWithControlPointsChanging(bool value); partial void OnIsWithControlPointsChanged(); partial void OnDivisionIDChanging(long value); partial void OnDivisionIDChanged(); partial void OnSHAPEChanging(string value); partial void OnSHAPEChanged(); #endregion public Block() { this.Initialize(); } [Column(Storage="_ID", AutoSync=AutoSync.OnInsert, DbType="BigInt NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)] [DataMember(Order=1)] public override long ID { get { return this._ID; } set { if ((this._ID != value)) { this.OnIDChanging(value); this.SendPropertyChanging(); this._ID = value; this.SendPropertyChanged("ID"); this.OnIDChanged(); } } } [Column(Storage="_StatusID", DbType="Int NOT NULL")] [DataMember(Order=2)] public int StatusID { get { return this._StatusID; } set { if ((this._StatusID != value)) { this.OnStatusIDChanging(value); this.SendPropertyChanging(); this._StatusID = value; this.SendPropertyChanged("StatusID"); this.OnStatusIDChanged(); } } } [Column(Storage="_Name", DbType="NVarChar(255)")] [DataMember(Order=3)] public string Name { get { return this._Name; } set { if ((this._Name != value)) { this.OnNameChanging(value); this.SendPropertyChanging(); this._Name = value; this.SendPropertyChanged("Name"); this.OnNameChanged(); } } } [Column(Storage="_IsWithControlPoints", DbType="Bit NOT NULL")] [DataMember(Order=4)] public bool IsWithControlPoints { get { return this._IsWithControlPoints; } set { if ((this._IsWithControlPoints != value)) { this.OnIsWithControlPointsChanging(value); this.SendPropertyChanging(); this._IsWithControlPoints = value; this.SendPropertyChanged("IsWithControlPoints"); this.OnIsWithControlPointsChanged(); } } } [Column(Storage="_DivisionID", DbType="BigInt NOT NULL")] [DataMember(Order=5)] public long DivisionID { get { return this._DivisionID; } set { if ((this._DivisionID != value)) { if (this._Division.HasLoadedOrAssignedValue) { throw new System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException(); } this.OnDivisionIDChanging(value); this.SendPropertyChanging(); this._DivisionID = value; this.SendPropertyChanged("DivisionID"); this.OnDivisionIDChanged(); } } } [Column(Storage="_SHAPE", DbType="Text", UpdateCheck=UpdateCheck.Never)] [DataMember(Order=6)] public string SHAPE { get { return this._SHAPE; } set { if ((this._SHAPE != value)) { this.OnSHAPEChanging(value); this.SendPropertyChanging(); this._SHAPE = value; this.SendPropertyChanged("SHAPE"); this.OnSHAPEChanged(); } } } [Association(Name="Block_BlockByWorkstation", Storage="_BlockByWorkstations", ThisKey="ID", OtherKey="BlockID")] [DataMember(Order=7, EmitDefaultValue=false)] public EntitySet<BlockByWorkstation> BlockByWorkstations { get { if ((this.serializing && (this._BlockByWorkstations.HasLoadedOrAssignedValues == false))) { return null; } return this._BlockByWorkstations; } set { this._BlockByWorkstations.Assign(value); } } [Association(Name="Block_PlanningPointAppropriation", Storage="_PlanningPointAppropriations", ThisKey="ID", OtherKey="MasterBlockID")] [DataMember(Order=8, EmitDefaultValue=false)] public EntitySet<PlanningPointAppropriation> PlanningPointAppropriations { get { if ((this.serializing && (this._PlanningPointAppropriations.HasLoadedOrAssignedValues == false))) { return null; } return this._PlanningPointAppropriations; } set { this._PlanningPointAppropriations.Assign(value); } } [Association(Name="Block_Neighbor", Storage="_Neighbors", ThisKey="ID", OtherKey="FirstBlockID")] [DataMember(Order=9, EmitDefaultValue=false)] public EntitySet<Neighbor> Neighbors { get { if ((this.serializing && (this._Neighbors.HasLoadedOrAssignedValues == false))) { return null; } return this._Neighbors; } set { this._Neighbors.Assign(value); } } [Association(Name="Block_Neighbor1", Storage="_Neighbors1", ThisKey="ID", OtherKey="SecondBlockID")] [DataMember(Order=10, EmitDefaultValue=false)] public EntitySet<Neighbor> Neighbors1 { get { if ((this.serializing && (this._Neighbors1.HasLoadedOrAssignedValues == false))) { return null; } return this._Neighbors1; } set { this._Neighbors1.Assign(value); } } [Association(Name="Block_Task", Storage="_Tasks", ThisKey="ID", OtherKey="BlockID")] [DataMember(Order=11, EmitDefaultValue=false)] public EntitySet<Task> Tasks { get { if ((this.serializing && (this._Tasks.HasLoadedOrAssignedValues == false))) { return null; } return this._Tasks; } set { this._Tasks.Assign(value); } } [Association(Name="Block_PlanningPointByBlock", Storage="_PlanningPointByBlocks", ThisKey="ID", OtherKey="BlockID")] [DataMember(Order=12, EmitDefaultValue=false)] public EntitySet<PlanningPointByBlock> PlanningPointByBlocks { get { if ((this.serializing && (this._PlanningPointByBlocks.HasLoadedOrAssignedValues == false))) { return null; } return this._PlanningPointByBlocks; } set { this._PlanningPointByBlocks.Assign(value); } } [Association(Name="Division_Block", Storage="_Division", ThisKey="DivisionID", OtherKey="ID", IsForeignKey=true, DeleteOnNull=true, DeleteRule="CASCADE")] public Division Division { get { return this._Division.Entity; } set { Division previousValue = this._Division.Entity; if (((previousValue != value) || (this._Division.HasLoadedOrAssignedValue == false))) { this.SendPropertyChanging(); if ((previousValue != null)) { this._Division.Entity = null; previousValue.Blocks.Remove(this); } this._Division.Entity = value; if ((value != null)) { value.Blocks.Add(this); this._DivisionID = value.ID; } else { this._DivisionID = default(long); } this.SendPropertyChanged("Division"); } } } public event PropertyChangingEventHandler PropertyChanging; public event PropertyChangedEventHandler PropertyChanged; protected virtual void SendPropertyChanging() { if ((this.PropertyChanging != null)) { this.PropertyChanging(this, emptyChangingEventArgs); } } protected virtual void SendPropertyChanged(String propertyName) { if ((this.PropertyChanged != null)) { this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } private void attach_BlockByWorkstations(BlockByWorkstation entity) { this.SendPropertyChanging(); entity.Block = this; } private void detach_BlockByWorkstations(BlockByWorkstation entity) { this.SendPropertyChanging(); entity.Block = null; } private void attach_PlanningPointAppropriations(PlanningPointAppropriation entity) { this.SendPropertyChanging(); entity.Block = this; } private void detach_PlanningPointAppropriations(PlanningPointAppropriation entity) { this.SendPropertyChanging(); entity.Block = null; } private void attach_Neighbors(Neighbor entity) { this.SendPropertyChanging(); entity.FirstBlock = this; } private void detach_Neighbors(Neighbor entity) { this.SendPropertyChanging(); entity.FirstBlock = null; } private void attach_Neighbors1(Neighbor entity) { this.SendPropertyChanging(); entity.SecondBlock = this; } private void detach_Neighbors1(Neighbor entity) { this.SendPropertyChanging(); entity.SecondBlock = null; } private void attach_Tasks(Task entity) { this.SendPropertyChanging(); entity.Block = this; } private void detach_Tasks(Task entity) { this.SendPropertyChanging(); entity.Block = null; } private void attach_PlanningPointByBlocks(PlanningPointByBlock entity) { this.SendPropertyChanging(); entity.Block = this; } private void detach_PlanningPointByBlocks(PlanningPointByBlock entity) { this.SendPropertyChanging(); entity.Block = null; } private void Initialize() { this._BlockByWorkstations = new EntitySet<BlockByWorkstation>(new Action<BlockByWorkstation>(this.attach_BlockByWorkstations), new Action<BlockByWorkstation>(this.detach_BlockByWorkstations)); this._PlanningPointAppropriations = new EntitySet<PlanningPointAppropriation>(new Action<PlanningPointAppropriation>(this.attach_PlanningPointAppropriations), new Action<PlanningPointAppropriation>(this.detach_PlanningPointAppropriations)); this._Neighbors = new EntitySet<Neighbor>(new Action<Neighbor>(this.attach_Neighbors), new Action<Neighbor>(this.detach_Neighbors)); this._Neighbors1 = new EntitySet<Neighbor>(new Action<Neighbor>(this.attach_Neighbors1), new Action<Neighbor>(this.detach_Neighbors1)); this._Tasks = new EntitySet<Task>(new Action<Task>(this.attach_Tasks), new Action<Task>(this.detach_Tasks)); this._PlanningPointByBlocks = new EntitySet<PlanningPointByBlock>(new Action<PlanningPointByBlock>(this.attach_PlanningPointByBlocks), new Action<PlanningPointByBlock>(this.detach_PlanningPointByBlocks)); this._Division = default(EntityRef<Division>); OnCreated(); } [OnDeserializing()] [System.ComponentModel.EditorBrowsableAttribute(EditorBrowsableState.Never)] public void OnDeserializing(StreamingContext context) { this.Initialize(); } [OnSerializing()] [System.ComponentModel.EditorBrowsableAttribute(EditorBrowsableState.Never)] public void OnSerializing(StreamingContext context) { this.serializing = true; } [OnSerialized()] [System.ComponentModel.EditorBrowsableAttribute(EditorBrowsableState.Never)] public void OnSerialized(StreamingContext context) { this.serializing = false; } }

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