Search Results

Search found 5941 results on 238 pages for 'entity beans'.

Page 65/238 | < Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >

  • Update one-to-many EntityKey using Foreign Key

    - by User.Anonymous
    To use by the easiest way Entity Framework, I use partial class to add Foreign Key on most important Entities Model. For example, I have an Entity "CONTACT" which have "TITLE", "FUNCTION" and others. When I update a CONTACT, with this code, Foreign Key are automatically updated : public int? TitId { get { if (this.TITLE_TIT != null) return TITLE_TIT.TIT_ID; return new Nullable<int>(); } set { this.TITLE_TITReference.EntityKey = new System.Data.EntityKey("Entities.TITLE_TIT", "TIT_ID", value); } } But I have a join with ACTIVITY, that can have many CONTACT, and I don't know how to update EntityKey on setters. public IEnumerable<EntityKeyMember> ActId { get { List<EntityKeyMember> lst = new List<EntityKeyMember>(); if (this.ACT_CON2 != null) { foreach (ACT_CON2 id in this.ACT_CON2.ToList()) { EntityKeyMember key = new EntityKeyMember(id.CON_ID.ToString(),id.ACT_ID); lst.Add(key); } } return lst; } set { this.ACT_CON2.EntityKey = new System.Data.EntityKey("Entities.ACT_CON2", value); } } How set many EntityKey ? Thank you.

    Read the article

  • EF + UnitOfWork + SharePoint RunWithElevatedPrivileges

    - by Lorenzo
    In our SharePoint application we have used the UnitOfWork + Repository patterns together with Entity Framework. To avoid the usage of the passthrough authentication we have developed a piece of code that impersonate a single user before creating the ObjectContext instance in a similar way that is described in "Impersonating user with Entity Framework" on this site. The only difference between our code and the referred question is that, to do the impersonation, we are using RunWithElevatedPrivileges to impersonate the Application Pool identity as in the following sample. SPSecurity.RunWithElevatedPrivileges(delegate() { using (SPSite site = new SPSite(url)) { _context = new MyDataContext(ConfigSingleton.GetInstance().ConnectionString); } }); We have done this way because we expected that creating the ObjectContext after impersonation and, due to the fact that Repositories are receiving the impersonated ObjectContext would solve our requirement. Unfortunately it's not so easy. In fact we experienced that, even if the ObjectContext is created before and under impersonation circumstances, the real connection is made just before executing the query, and so does not use impersonation, which break our requirement. I have checked the ObjectContext class to see if there was any event through which we can inject the impersonation but unfortunately found nothing. Any help?

    Read the article

  • Hibernate and parent/child relations

    - by Marco
    Hi to all, I'm using Hibernate in a Java application, and i feel that something could be done better for the management of parent/child relationships. I've a complex set of entities, that have some kind of relationships between them (one-to-many, many-to-many, one-to-one, both unidirectional and bidirectional). Every time an entity is saved and it has a parent, to estabilish the relationship the parent has to add the child to its collection (considering a one-to-may relationship). For example: Parent p = (Parent) session.load(Parent.class, pid); Child c = new Child(); c.setParent(p); p.getChildren().add(c); session.save(c); session.flush(); In the same way, if i remove a child then i have to explicitly remove it from the parent collection too. Child c = (Child) session.load(Child.class, cid); session.delete(c); Parent p = (Parent) session.load(Parent.class, pid); p.getChildren().remove(c); session.flush(); I was wondering if there are some best practices out there to do this jobs in a different way: when i save a child entity, automatically add it to the parent collection. If i remove a child, automatically update the parent collection by removing the child, etc. For example, Child c = new Child(); c.setParent(p); session.save(c); // Automatically update the parent collection session.flush(); or Child c = (Child) session.load(Child.class, cid); session.delete(c); // Automatically updates its parents (could be more than one) session.flush(); Anyway, it would not be difficult to implement this behaviour, but i was wondering if exist some standard tools or well known libraries that deals with this issue. And, if not, what are the reasons? Thanks

    Read the article

  • What is the best database structure for this scenario?

    - by Ricketts
    I have a database that is holding real estate MLS (Multiple Listing Service) data. Currently, I have a single table that holds all the listing attributes (price, address, sqft, etc.). There are several different property types (residential, commercial, rental, income, land, etc.) and each property type share a majority of the attributes, but there are a few that are unique to that property type. My question is the shared attributes are in excess of 250 fields and this seems like too many fields to have in a single table. My thought is I could break them out into an EAV (Entity-Attribute-Value) format, but I've read many bad things about that and it would make running queries a real pain as any of the 250 fields could be searched on. If I were to go that route, I'd literally have to pull all the data out of the EAV table, grouped by listing id, merge it on the application side, then run my query against the in memory object collection. This also does not seem very efficient. I am looking for some ideas or recommendations on which way to proceed. Perhaps the 250+ field table is the only way to proceed. Just as a note, I'm using SQL Server 2012, .NET 4.5 w/ Entity Framework 5, C# and data is passed to asp.net web application via WCF service. Thanks in advance.

    Read the article

  • How to avoid using the same identifier for Class Names and Property Names?

    - by Wololo
    Here are a few example of classes and properties sharing the same identifier: public Coordinates Coordinates { get; set; } public Country Country { get; set; } public Article Article { get; set; } public Color Color { get; set; } public Address Address { get; set; } This problem occurs more frequently when using POCO with the Entity Framework as the Entity Framework uses the Property Name for the Relationships. So what to do? Use non-standard class names? public ClsCoordinates Coordinates { get; set; } public ClsCountry Country { get; set; } public ClsArticle Article { get; set; } public ClsColor Color { get; set; } public ClsAddress Address { get; set; } public ClsCategory Category { get; set; } Yuk Or use more descriptive Property Names? public Coordinates GeographicCoordinates { get; set; } public Country GeographicCountry { get; set; } public Article WebArticle { get; set; } public Color BackgroundColor { get; set; } public Address HomeAddress { get; set; } public Category ProductCategory { get; set; } Less than ideal, but can live with it I suppose. Or JUST LIVE WITH IT? What are you best practices?

    Read the article

  • Does Hibernate support one-to-one associations as pkeys?

    - by Andrzej Doyle
    Hi all, Can anyone tell me whether Hibernate supports associations as the pkey of an entity? I thought that this would be supported but I am having a lot of trouble getting any kind of mapping that represents this to work. In particular, with the straight mapping below: @Entity public class EntityBar { @Id @OneToOne(optional = false, mappedBy = "bar") EntityFoo foo // other stuff } I get an org.hibernate.MappingException: "Could not determine type for: EntityFoo, at table: ENTITY_BAR, for columns: [org.hibernate.mapping.Column(foo)]" Diving into the code it seems the ID is always considered a Value type; i.e. "anything that is persisted by value, instead of by reference. It is essentially a Hibernate Type, together with zero or more columns." I could make my EntityFoo a value type by declaring it serializable, but I wouldn't expect this would lead to the right outcome either. I would have thought that Hibernate would consider the type of the column to be integer (or whatever the actual type of the parent's ID is), just like it would with a normal one-to-one link, but this doesn't appear to kick in when I also declare it an ID. Am I going beyond what is possible by trying to combine @OneToOne with @Id? And if so, how could one model this relationship sensibly?

    Read the article

  • How to create view model without sorting collections in memory.

    - by Chevex
    I have a view model (below). public class TopicsViewModel { public Topic Topic { get; set; } public Reply LastReply { get; set; } } I want to populate an IQueryable<TopicsViewModel> with values from my IQueryable<Topic> collection and IQueryable<Reply> collection. I do not want to use the attached entity collection (i.e. Topic.Replies) because I only want the last reply for that topic and doing Topic.Replies.Last() loads the entire entity collection in memory and then grabs the last one in the list. I am trying to stay in IQueryable so that the query is executed in the database. I also don't want to foreach through topics and query replyRepository.Replies because looping through IQueryable<Topic> will start the lazy loading. I'd prefer to build one expression and have all the leg work done in the lower layers. I have the following: IQueryable<TopicsViewModel> topicsViewModel = from x in topicRepository.Topics from y in replyRepository.Replies where y.TopicID == x.TopicID orderby y.PostedDate ascending select new TopicsViewModel { Topic = x, LastReply = y }; But this isn't working. Any ideas how I can populate an IQueryable or IEnumerable of TopicsViewModel so that it queries the database and grabs topics and that topic's last reply? I am trying really hard to avoid grabbing all replies related to that topic. I only want to grab the last reply. Thank you for any insight you have to offer.

    Read the article

  • Data layer refactoring

    - by Joey
    I've taken control of some entity framework code and am looking to refactor it. Before I do, I'd like to check my thoughts are correct and I'm not missing the entity-framework way of doing things. Example 1 - Subquery vs Join Here we have a one-to-many between As and Bs. Apart from the code below being hard to read, is it also inefficient? from a in dataContext.As where ((from b in dataContext.Bs where b.Text.StartsWith(searchText) select b.AId).Distinct()).Contains(a.Id) select a Would it be better, for example, to use the join and do something like this? from a in dataContext.As where a.Bs.Any(b => b.Text.StartsWith(searchText)) select a Example 2 - Explicit Joins vs Navigation Here we have a one-to-many between As and Bs and a one-to-many between Bs and Cs. from a in dataContext.As join b in dataContext.Bs on b.AId equals a.Id join c in dataContext.Cs on c.BId equals b.Id where c.SomeValue equals searchValue select a Is there a good reason to use explicit joins rather than navigating through the data model? For example: from a in dataContext.As where a.Bs.Any(b => b.Cs.Any(c => c.SomeValue == searchValue) select a

    Read the article

  • I need help solving a rather weird error in a WCF service.

    - by Moulde
    Hi.. I have a solution that contains three projects. A main project with my MVC app, a silverlight application and a (silverlight enabled) WCF service project. In my silverlight project i have made a Service Reference to my WCF service. And i pretty much got that working. In my WCF service i have a method that returns an Book object, which got some random fields like title, date etc. In the book class, i have a ICollection field that contains a list of events. The book class is generated using entity framework 4.0, and Lazy Loading is enabled. If i in my getBook(int id) method return a book with the events field not initialized, it works as a charm. But if i initialize the field, i'm getting this error. The server did not provide a meaningful reply; this might be caused by a contract mismatch, a premature session shutdown or an internal server error. I have a few ideas why that is happening, and while writing this i just got another one. The wcf service somehow threw away the reference to the event class. That would be very weird since i have a reference between my main mvc app (with the models) and my WCF service. Since i have enabled lazy loading in EF 4.0, i suspect that it may be the thing generating the error. But i'm not sure why that would be, because i'm not in any way accessing that field. I could understand that i may not be able to access the events field after i recive the object in my silverlight application since the connection between the book object and the entity framework is like broken. Did i mention that Lazy Loading is enabled on my EF instance? And there is no inner exception in the thrown exception. Thanks in advance. Malte Baden Hansen

    Read the article

  • Advice on Minimizing Stored Procedure Parameters

    - by RPM1984
    Hi Guys, I have an ASP.NET MVC Web Application that interacts with a SQL Server 2008 database via Entity Framework 4.0. On a particular page, i call a stored procedure in order to pull back some results based on selections on the UI. Now, the UI has around 20 different input selections, ranging from a textbox, dropdown list, checkboxes, etc. Each of those inputs are "grouped" into logical sections. Example: Search box : "Foo" Checkbox A1: ticked, Checkbox A2: unticked Dropdown A: option 3 selected Checkbox B1: ticked, Checkbox B2: ticked, Checkbox B3: unticked So i need to call the SPROC like this: exec SearchPage_FindResults @SearchQuery = 'Foo', @IncludeA1 = 1, @IncludeA2 = 0, @DropDownSelection = 3, @IncludeB1 = 1, @IncludeB2 = 1, @IncludeB3 = 0 The UI is not too important to this question - just wanted to give some perspective. Essentially, i'm pulling back results for a search query, filtering these results based on a bunch of (optional) selections a user can filter on. Now, My questions/queries: What's the best way to pass these parameters to the stored procedure? Are there any tricks/new ways (e.g SQL Server 2008) to do this? Special "table" parameters/arrays - can we pass through User-Defined-Types? Keep in mind im using Entity Framework 4.0 - but could always use classic ADO.NET for this if required. What about XML? What are the serialization/de-serialization costs here? Is it worth it? How about a parameter for each logical section? Comma-seperated perhaps? Just thinking out loud. This page is particulary important from a user point of view, and needs to perform really well. The stored procedure is already heavy in logic, so i want to minimize the performance implications - so keep that in mind. With that said - what is the best approach here?

    Read the article

  • EF code first error "The specified index already exists. [ IX_Id ]" for object tree

    - by PascalN
    Using EF code first 4.3 I'm trying to model an object tree with a required-required relationships and a required-optional relationships. Here is a simple representation of those classes public class Top { public int Id { get; set; } public virtual Middle Middle { get; set; } } public class Middle { public int Id { get; set; } public virtual Child Child { get; set; } } public class Child { public int Id { get; set; } } Here is the OnModelCreating code modelBuilder.Entity<Top>().HasRequired(t => t.Middle).WithRequiredPrincipal().WillCascadeOnDelete(); modelBuilder.Entity<Middle>().HasRequired(t => t.Child).WithOptional().WillCascadeOnDelete(); This produces the error "The specified index already exists. [ IX_Id ]" on SQLCE After checking the db schema, both model binder fluent API configuration lines create an index IX_Id on the table Middles. Does anyone know how to work around that problem? Is there a way to set the index name? Thank you! Pascal

    Read the article

  • Driving me INSANE: Unable to Retrieve Metadata for

    - by Loren
    I've been spending the past 3 days trying to fix this problem I'm encountering - it's driving me insane... I'm not quite sure what is causing this bug - here are the details: MVC4 + Entity Framework 4.4 + MySql + POCO/Code First I'm setting up the above configuration .. here are my classes: namespace BTD.DataContext { public class BTDContext : DbContext { public BTDContext() : base("name=BTDContext") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); //modelBuilder.Conventions.Remove<System.Data.Entity.Infrastructure.IncludeMetadataConvention>(); } public DbSet<Product> Products { get; set; } public DbSet<ProductImage> ProductImages { get; set; } } } namespace BTD.Data { [Table("Product")] public class Product { [Key] public long ProductId { get; set; } [DisplayName("Manufacturer")] public int? ManufacturerId { get; set; } [Required] [StringLength(150)] public string Name { get; set; } [Required] [DataType(DataType.MultilineText)] public string Description { get; set; } [Required] [StringLength(120)] public string URL { get; set; } [Required] [StringLength(75)] [DisplayName("Meta Title")] public string MetaTitle { get; set; } [DataType(DataType.MultilineText)] [DisplayName("Meta Description")] public string MetaDescription { get; set; } [Required] [StringLength(25)] public string Status { get; set; } [DisplayName("Create Date/Time")] public DateTime CreateDateTime { get; set; } [DisplayName("Edit Date/Time")] public DateTime EditDateTime { get; set; } } [Table("ProductImage")] public class ProductImage { [Key] public long ProductImageId { get; set; } public long ProductId { get; set; } public long? ProductVariantId { get; set; } [Required] public byte[] Image { get; set; } public bool PrimaryImage { get; set; } public DateTime CreateDateTime { get; set; } public DateTime EditDateTime { get; set; } } } Here is my web.config setup... <connectionStrings> <add name="BTDContext" connectionString="Server=localhost;Port=3306;Database=btd;User Id=root;Password=mypassword;" providerName="MySql.Data.MySqlClient" /> </connectionStrings> The database AND tables already exist... I'm still pretty new with mvc but was using this tutorial The application builds fine.. however when I try to add a controller using Product (BTD.Data) as my model class and BTDContext (BTD.DataContext) as my data context class I receive the following error: Unable to retrieve metadata for BTD.Data.Product using the same DbCompiledModel to create context against different types of database servers is not supported. Instead, create a separate DbCompiledModel for each type of server being used. I am at a complete loss - I've scoured google with almost every different variation of that error message above I can think of but to no avail. Here are the things i can verify... MySql is working properly I'm using MySql Connector version 6.5.4 and have created other ASP.net web forms + entity framework applications with ZERO problems I have also tried including/removing this in my web.config: <system.data> <DbProviderFactories> <remove invariant="MySql.Data.MySqlClient"/> <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.5.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" /> </DbProviderFactories> I've literally been working on this bug for days - I'm to the point now that I would be willing to pay someone to solve it.. no joke... I'd really love to use MVC 4 and Razor - I was so excited to get started on this, but now i'm pretty discouraged - I truly appreciate any help/guidance on this! Also note - i'm using Entityframework from Nuget... Another Note I was using the default visual studio template that creates your MVC project with the account pages and other stuff. I JUST removed all references to the added files because they were trying to use the "DefaultConnection" which didn't exist - so i thought those files may be what was causing the error - however still no luck after removing them - I just wanted to let everyone know i'm using the visual studio MVC project template which pre-creates a bunch of files. I will be trying to recreate this all from a blank MVC project which doesn't have those files - i will update this once i test that Other References It appears someone else is having the same issues I am - the only difference is they are using sql server - I tried tweaking all my code to follow the suggestions on this stackoverflow question/answer here but still to no avail

    Read the article

  • LLBLGen Pro v3.1 released!

    - by FransBouma
    Yesterday we released LLBLGen Pro v3.1! Version 3.1 comes with new features and enhancements, which I'll describe briefly below. v3.1 is a free upgrade for v3.x licensees. What's new / changed? Designer Extensible Import system. An extensible import system has been added to the designer to import project data from external sources. Importers are plug-ins which import project meta-data (like entity definitions, mappings and relational model data) from an external source into the loaded project. In v3.1, an importer plug-in for importing project elements from existing LLBLGen Pro v3.x project files has been included. You can use this importer to create source projects from which you import parts of models to build your actual project with. Model-only relationships. In v3.1, relationships of the type 1:1, m:1 and 1:n can be marked as model-only. A model-only relationship isn't required to have a backing foreign key constraint in the relational model data. They're ideal for projects which have to work with relational databases where changes can't always be made or some relationships can't be added to (e.g. the ones which are important for the entity model, but are not allowed to be added to the relational model for some reason). Custom field ordering. Although fields in an entity definition don't really have an ordering, it can be important for some situations to have the entity fields in a given order, e.g. when you use compound primary keys. Field ordering can be defined using a pop-up dialog which can be opened through various ways, e.g. inside the project explorer, model view and entity editor. It can also be set automatically during refreshes based on new settings. Command line relational model data refresher tool, CliRefresher.exe. The command line refresh tool shipped with v2.6 is now available for v3.1 as well Navigation enhancements in various designer elements. It's now easier to find elements like entities, typed views etc. in the project explorer from editors, to navigate to related entities in the project explorer by right clicking a relationship, navigate to the super-type in the project explorer when right-clicking an entity and navigate to the sub-type in the project explorer when right-clicking a sub-type node in the project explorer. Minor visual enhancements / tweaks LLBLGen Pro Runtime Framework Entity creation is now up to 30% faster and takes 5% less memory. Creating an entity object has been optimized further by tweaks inside the framework to make instantiating an entity object up to 30% faster. It now also takes up to 5% less memory than in v3.0 Prefetch Path node merging is now up to 20-25% faster. Setting entity references required the creation of a new relationship object. As this relationship object is always used internally it could be cached (as it's used for syncing only). This increases performance by 20-25% in the merging functionality. Entity fetches are now up to 20% faster. A large number of tweaks have been applied to make entity fetches up to 20% faster than in v3.0. Full WCF RIA support. It's now possible to use your LLBLGen Pro runtime framework powered domain layer in a WCF RIA application using the VS.NET tools for WCF RIA services. WCF RIA services is a Microsoft technology for .NET 4 and typically used within silverlight applications. SQL Server DQE compatibility level is now per instance. (Usable in Adapter). It's now possible to set the compatibility level of the SQL Server Dynamic Query Engine (DQE) per instance of the DQE instead of the global setting it was before. The global setting is still available and is used as the default value for the compatibility level per-instance. You can use this to switch between CE Desktop and normal SQL Server compatibility per DataAccessAdapter instance. Support for COUNT_BIG aggregate function (SQL Server specific). The aggregate function COUNT_BIG has been added to the list of available aggregate functions to be used in the framework. Minor changes / tweaks I'm especially pleased with the import system, as that makes working with entity models a lot easier. The import system lets you import from another LLBLGen Pro v3 project any entity definition, mapping and / or meta-data like table definitions. This way you can build repository projects where you store model fragments, e.g. the building blocks for a customer-order system, a user credential model etc., any model you can think of. In most projects, you'll recognize that some parts of your new model look familiar. In these cases it would have been easier if you would have been able to import these parts from projects you had pre-created. With LLBLGen Pro v3.1 you can. For example, say you have an Oracle schema called CRM which contains the bread 'n' butter customer-order-product kind of model. You create an entity model from that schema and save it in a project file. Now you start working on another project for another customer and you have to use SQL Server. You also start using model-first development, so develop the entity model from scratch as there's no existing database. As this customer also requires some CRM like entity model, you import the entities from your saved Oracle project into this new SQL Server targeting project. Because you don't work with Oracle this time, you don't import the relational meta-data, just the entities, their relationships and possibly their inheritance hierarchies, if any. As they're now entities in your project you can change them a bit to match the new customer's requirements. This can save you a lot of time, because you can re-use pre-fab model fragments for new projects. In the example above there are no tables yet (as you work model first) so using the forward mapping capabilities of LLBLGen Pro v3 creates the tables, PK constraints, Unique Constraints and FK constraints for you. This way you can build a nice repository of model fragments which you can re-use in new projects.

    Read the article

  • How to choose cell to put entity in in an uniform grid used for broad phase collision detection?

    - by nathan
    I'm trying to implement the broad phase of my collision detection algorithm. My game is an arcade game with lot of moving entities in an open space with relatively equivalent sizes. Regarding the above specifications, i decided to use an uniform grid for space partitioning. The problem i have right know is how to efficiently choose in which cells an entity should be added. ATM i'm doing something like this: for (int x = 0; x < gridSize; x++) { for (int y = 0; y < gridSize; y++) { GridCell cell = grid[x][y]; cell.clear(); //remove the previously added entities for (int i = 0; i < entities.size(); i++) { Entity e = entities.get(i); if (cell.isEntityOverlap(e)) { cell.add(e); } } } } The isEntityOverlap is a simple method i added my GridCell class. public boolean isEntityOverlap(Shape s) { return cellArea.intersects(s); } Where cellArea is a Rectangle. cellArea = new Rectangle(x, y, CollisionGrid.CELL_SIZE, CollisionGrid.CELL_SIZE); It works but it's damn slow. What would be a fast way to know all the cells an entity overlaps? Note: by "it works" i mean, the entities are contained in the good cells over the time after movements etc.

    Read the article

  • Finally! Entity Framework working in fully disconnected N-tier web app

    - by oazabir
    Entity Framework was supposed to solve the problem of Linq to SQL, which requires endless hacks to make it work in n-tier world. Not only did Entity Framework solve none of the L2S problems, but also it made it even more difficult to use and hack it for n-tier scenarios. It’s somehow half way between a fully disconnected ORM and a fully connected ORM like Linq to SQL. Some useful features of Linq to SQL are gone – like automatic deferred loading. If you try to do simple select with join, insert, update, delete in a disconnected architecture, you will realize not only you need to make fundamental changes from the top layer to the very bottom layer, but also endless hacks in basic CRUD operations. I will show you in this article how I have  added custom CRUD functions on top of EF’s ObjectContext to make it finally work well in a fully disconnected N-tier web application (my open source Web 2.0 AJAX portal – Dropthings) and how I have produced a 100% unit testable fully n-tier compliant data access layerfollowing the repository pattern. http://www.codeproject.com/KB/linq/ef.aspx In .NET 4.0, most of the problems are solved, but not all. So, you should read this article even if you are coding in .NET 4.0. Moreover, there’s enough insight here to help you troubleshoot EF related problems. You might think “Why bother using EF when Linq to SQL is doing good enough for me.” Linq to SQL is not going to get any innovation from Microsoft anymore. Entity Framework is the future of persistence layer in .NET framework. All the innovations are happening in EF world only, which is frustrating. There’s a big jump on EF 4.0. So, you should plan to migrate your L2S projects to EF soon.

    Read the article

  • Poll on Entity Framework 4 &ndash; one year on

    - by Eric Nelson
    12 months back (today is March 15th 2010) on the 16th of  March 2009 I created a poll on Entity Framework v1 – the marmite of ORMs? A quick poll…. Entity Framework v1 was getting a mixed reception at the time – I met developers who genuinely hated it and I met developers who were loving the productivity improvements they were seeing. There were definitely issues with v1, too many IMHO. Which is why the product team placed a huge effort on listening to the community to drive the feature set for v2 (which ultimately was named Entity Framework 4 as it ships with .NET 4). I think overall the team have done a great job. It isn’t perfect in .NET 4 (which is why the team are busy on post .NET 4 improvements) but I would happily use it and recommend it for a wide variety of projects – much wider than I would have with v1. I am speaking on EF 4 at www.devweek.com this Wednesday and I thought it would be fun to put a new version of the poll out and see how v4 is being received. Obviously the big difference is we have not yet shipped EF4 vs when I did the original poll on EF1. March 2010 poll – please vote Summary of March 2009 poll – it was a tie between positive and negative Total votes 150 Positive about EF v1 42 (15 + 19 + 8) Negative about EF v1  43 (34 + 9)

    Read the article

  • Concatenate int and string in LINQ

    - by Waheed
    HI, I am using the following code from c in Country where c.IsActive.Equals(true) orderby c.CountryName select new { countryIDCode = c.CountryID + "|" + c.TwoDigitCode, countryName = c.CountryName } but following is the error while doing this... Unable to cast the type 'System.Int32' to type 'System.Object'. LINQ to Entities only supports casting Entity Data Model primitive types. CountryID is int type and TwoDigitCode is string type. Can u please let me know how to concatenate.... Thanks....

    Read the article

  • Implicit Lazy Loading vs Explicit Lazy Loading

    - by Tarik
    I've been reading Entity Framework and people were crying over why there was not implicit lazy loading or something. Basically I've been searching things about Lazy Loading and now I know what it is : It is a design pattern which allows us to load objects when they are really needed. But what is the difference between Explicit Lazy Loading and Implicit Lazy Loading. Thanks in advance...

    Read the article

  • Converting sql query to EF query - nested query in from

    - by vdh_ant
    Hey guys Just wondering how the following sql query would look in linq for Entity Framework... SELECT KPI.* FROM KeyPerformanceIndicator KPI INNER JOIN ( SELECT SPP.SportProgramPlanId FROM SportProgramPlan PSPP INNER JOIN SportProgramPlan ASPP ON (PSPP.SportProgramPlanId = @SportProgramPlanId AND PSPP.StartDate >= ASPP.StartDate AND PSPP.EndDate <= ASPP.EndDate ) AS SPP ON KPI.SportProgramPlanId = SPP.SportProgramPlanId Cheers Anthony

    Read the article

  • Cross-table linq query with EF4/POCO

    - by Basiclife
    Hi All, I'm new to EF(any version) and POCO. I'm trying to use POCO entities with a generic repository in a "code-first" mode(?) I've got some POCO Entities (no proxies, no lazy loading, nothing). I have a repository(of T as Entity) which provides me with basic get/getsingle/getfirst functionality which takes a lambda as a parameter (specifically a System.Func(Of T, Boolean)) Now as I'm returning the simplest possible POCO object, none of the relationship parameters work once they've been retrieved from the database (as I would expect). However, I had assumed (wrongly) that my lambda query passed to the repository would be able to use the links between entities as it would be executed against the DB before the simple POCO entities are generated. The flow is: GUI calls: Public Function GetAllTypesForCategory(ByVal CategoryID As Guid) As IEnumerable(Of ItemType) Return ItemTypeRepository.Get(Function(x) x.Category.ID = CategoryID) End Function Get is defined in Repository(of T as Entity): Public Function [Get](ByVal Query As System.Func(Of T, Boolean)) As IEnumerable(Of T) Implements Interfaces.IRepository(Of T).Get Return ObjectSet.Where(Query).ToList() End Function The code doesn't error when this method is called but does when I try to use the result set. (This seems to be a lazy loading behaviour so I tried adding the .ToList() to force eager loading - no difference) I'm using unity/IOC to wire it all up but I believe that's irrelevant to the issue I'm having NB: Relationships between entities are being configured properly and if I turn on proxies/lazy loading/etc... this all just works. I'm intentionally leaving all that turned off as some calls to the BL will be from a website but some will be via WCF - So I want the simplest possible objects. Also, I don't want a change in an object passed to the UI to be committed to the DB if another BL method calls Commit() Can someone please either point out how to make this work or explain why it's not possible? All I want to do is make sure the lambda I pass in is performed against the DB before the results are returned Many thanks. In case it matters, the container is being populated with everything as shown below: Container.AddNewExtension(Of EFRepositoryExtension)() Container.Configure(Of IEFRepositoryExtension)(). WithConnection(ConnectionString). WithContextLifetime(New HttpContextLifetimeManager(Of IObjectContext)()). ConfigureEntity(New CategoryConfig(), "Categories"). ConfigureEntity(New ItemConfig()). ... )

    Read the article

  • "like" queries in ASP.net MVC

    - by sslepian
    How do I get wildcard text searches (like SQL's "like" statement) in ASP.net MVC using the edo entity framework? I assumed this would work: var elig = (from e in _documentDataModel.Protocol_Eligibility_View where e.criteria.Contains(query) select e); But it returns no results even when searching for a query string that's definitely in the database. What am I doing wrong?

    Read the article

  • deploying applications that use LINQ to Entities.

    - by Luiscencio
    HI COMUNITY!!!! I want to use L2E since it s very convenient to my company's apps, I created a demo project, the demo does run on every machine but when I, lets say, press a button that has some code that uses the entity I get this error: specified store provider cannot be found in the configuration, or is not valid. note that I get this error only on machines that does not have VS2008 installed, on these machines (the ones with VS2008) the demo works well. any advice is appreciated.

    Read the article

  • Shawn Wildermuth violating MVVM in MSDN article?

    - by rasx
    This may be old news but back in March 2009, Shawn Wildermuth, his article, “Model-View-ViewModel In Silverlight 2 Apps,” has a code sample that includes DataServiceEntityBase: // COPIED FROM SILVERLIGHTCONTRIB Project for simplicity /// <summary> /// Base class for DataService Data Contract classes to implement /// base functionality that is needed like INotifyPropertyChanged. /// Add the base class in the partial class to add the implementation. /// </summary> public abstract class DataServiceEntityBase : INotifyPropertyChanged { /// <summary> /// The handler for the registrants of the interface's event /// </summary> PropertyChangedEventHandler _propertyChangedHandler; /// <summary> /// Allow inheritors to fire the event more simply. /// </summary> /// <param name="propertyName"></param> protected void FirePropertyChanged(string propertyName) { if (_propertyChangedHandler != null) { _propertyChangedHandler(this, new PropertyChangedEventArgs(propertyName)); } } #region INotifyPropertyChanged Members /// <summary> /// The interface used to notify changes on the entity. /// </summary> event PropertyChangedEventHandler INotifyPropertyChanged.PropertyChanged { add { _propertyChangedHandler += value; } remove { _propertyChangedHandler -= value; } } #endregion What this class implies is that the developer intends to bind visuals directly to data (yes, a ViewModel is used but it defines an ObservableCollection of data objects). Is this design diverging too far from the guidance of MVVM? Now I can see some of the reasons why Shawn would go this way: what Shawn can do with DataServiceEntityBase is this sort of thing (which is intimate with the Entity Framework): // Partial Method to support the INotifyPropertyChanged interface public partial class Game : DataServiceEntityBase { #region Partial Method INotifyPropertyChanged Implementation // Override the Changed partial methods to implement the // INotifyPropertyChanged interface // This helps with the Model implementation to be a mostly // DataBound implementation partial void OnDeveloperChanged() { base.FirePropertyChanged("Developer"); } partial void OnGenreChanged() { base.FirePropertyChanged("Genre"); } partial void OnListPriceChanged() { base.FirePropertyChanged("ListPrice"); } partial void OnListPriceCurrencyChanged() { base.FirePropertyChanged("ListPriceCurrency"); } partial void OnPlayerInfoChanged() { base.FirePropertyChanged("PlayerInfo"); } partial void OnProductDescriptionChanged() { base.FirePropertyChanged("ProductDescription"); } partial void OnProductIDChanged() { base.FirePropertyChanged("ProductID"); } partial void OnProductImageUrlChanged() { base.FirePropertyChanged("ProductImageUrl"); } partial void OnProductNameChanged() { base.FirePropertyChanged("ProductName"); } partial void OnProductTypeIDChanged() { base.FirePropertyChanged("ProductTypeID"); } partial void OnPublisherChanged() { base.FirePropertyChanged("Publisher"); } partial void OnRatingChanged() { base.FirePropertyChanged("Rating"); } partial void OnRatingUrlChanged() { base.FirePropertyChanged("RatingUrl"); } partial void OnReleaseDateChanged() { base.FirePropertyChanged("ReleaseDate"); } partial void OnSystemNameChanged() { base.FirePropertyChanged("SystemName"); } #endregion } Of course MSDN code can seen as “toy code” for educational purposes but is anyone doing anything like this in the real world of Silverlight development?

    Read the article

  • linking the EF 4.0 context to the WCF call context

    - by pablocastilla
    Hello, I would like to create an Entity Framework 4.0 context when a call is received and invoke to save changes when it finish, (something like JPA). I think it is a good idea because I can use the state for all the call, It is short and encapsulate enogh to be threadsafe and long enough for caching calls and the context itself. Any idea how is the best way for implement this?

    Read the article

< Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >