entity-framework-4

Overview I am using entity framework 4.3 code first with the fluent interface to setup my DbContext. I have a base Item class with other types that inherit this such as an Event , BlogPost , ForumThread , WikiPage and so on. These inherited types are mapped with what I think entity framework refers to as TPT inheritance. This works great when querying a single type like 'events' or 'blog posts' but constructs very complicated queries with horrible performance when trying to query across all types due to the joins required in order to achieve the polymorphic behaviour EF provides out of the box

What I am trying to do is basically what NHibernate does when you do something like: var instance = session.Get<Customer>(id, LockMode.Upgrade); I need to lock the entity row in the database. Why I need that? Imagine something like a workflow instance that can be updated by multiple actors(people or processes) at the same time. The constraints I have don't allow for optimistic locking solutions. EF doesn't have support for this. If you want to lock some record by query you must do something like: using (var scope = new TransactionScope(...)) { using (var context = new YourContext(...)) { var

I have an EF4 Model that is built with abstract entities/classes: Notice how State entity has a navigational property called Country . Note: I have lazy-loading disabled, so i must eager-load on demand. Now, if i have the following method: public Location FindSingle(int id) { return _repository.Find().WithId(id).SingleOrDefault(); } This does not return any associations by default. But how can i dynamically eager-load the associations when i explicitly want to? I cannot do this: return _repository.Find().WithId(id).Include("Country").SingleOrDefault(); As i am working with an abstract class

Ack! I'm new to Entity Framework and am trying to find the simplest way to delete an item. I have a listbox with the datasource set to TagCategory objects from the database. This is working fine. Now I'd like to delete the selected item. So I do something like this: TagCategory category = (TagCategory)lstCategories.SelectedItem; using (MyEntities context = new MyEntities()) { context.AttachTo("TagCategories", category); context.DeleteObject(category); context.SaveChanges(); } This seems straight forward enough, but it doesn't work. Nothing is deleted, no error message, nothing. So I see I can

This one has me stumped. I have a Customer and Order entity. the Customer can have many Orders. Where the Customer has 10,000 orders when I create a new Order and set the Customer property (Order.Customer = customer) there is a LONG delay (20s of seconds). It appears that the context is loading all 10,000 orders before adding this new one. I am not currently using FKs directly which I suspect may help. Any ideas how I can improve matters without a massive refactor? Cheers. The problem is most probably that you are using T4 POCO template. This template generates nasty fixup methods and use them

I am new to ASP.NET MVC, I am facing this exception, the connection string looks perfect but still, the exception is raised, appreciate if anyone give me why is happening. Thank you guys Model 1 namespace MVCTwice.Models { public class StudentContext : DbContext { public DbSet<Student> studs { get; set; } } } Model 2 namespace MVCTwice.Models { [Table("tblStudents")] public class Student { public int id { get; set; } public string name { get; set; } public string gender { get; set; } public string totalMarks { get; set; } } } Action method public ActionResult Index() { StudentContext