entity-framework-ctp5

How would I map something like this using the modelBuilder? Where theres a nullable foreign key referencing the same tables primary key Table: Task taskID int pk taskName varchar parentTaskID int (nullable) FK Task class: public class Task { public int taskID {get;set;} public string taskName {get;set;} public int parentTaskID {get;set;} public Task parentTask {get;set;} } ... modelBuilder.Entity<Task>() .HasOptional(o => o.ParentTask).... The following code gives you the desired schema. Note that you also need to define ParentTaskID foreign key as a nullable integer, like I did below. public

I saw this comment on MSDN ( link and link ): "Note that Independent Associations should often be avoided since things like N-Tier and concurrency becomes more difficult." I'm new to EF4 and I'm building an n-Tier web app. This sounds like an important pitfall. Can someone explain to me what this means? I think it's personal preference. Originally, EF was created to only use indep. associations and aligned with a more classic ERM approach. However, most of us devs are so dependent on FKs that it made life very complex. So MS gave us FKs in EF4 which meant not only having the FK as a property

Using Entity Framework Code First CTP5, how do I create a primary key column that are INTs and are not identity columns Preferably not using attributes. Matt Hamilton If you're building your entities using the fluent interface rather than using attributes over the properties, you may be able to use the DatabaseGenerationOption class (from EntityFramework.dll, in the System.ComponentModel.DataAnnotations namespace). I've not tested it, but this is what it would look like: modelBuilder .Entity<Foo>() .Property(f => f.Id) .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None); That answer didn

I am following this article on MSDN. I ported it to EF Code First. public interface IUnitOfWork { IRepository<Employee> Employees { get; } IRepository<TimeCard> TimeCards { get; } void Commit(); } public class HrContext : DbContext { public DbSet<Employee> Employees { get; set; } public DbSet<TimeCard> TimeCards { get; set; } protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<Employee>() .HasMany(e => e.TimeCards) .WithOptional(tc => tc.Employee); } } public class SqlRepository<T> : IRepository<T> where T : class { private readonly DbSet<T> entitySet;

I a portion of my EF model that looks like this: Summary: Location has many Posts Post is an abstract class Discussion derives from Post Discussions have many Comments Now, the query i'm trying to achieve: Get information about Location Id 1234, including any Discussions and Comments associated with those Discussions. I can get discussions and the comments like this: var discussions = ctx.Posts .OfType<Discussion>() .Include(x => x.Comments) .ToList(); But i can't seem to get it based on the Posts navigation on the Location entity. I've tried this: var locationWithDiscussionsAndComments = ctx

I have the following scenario in my database. It is a record of Studies and those studies have other studies as prerequisites. In my DB design, it looks like this: And my code looks something like this: public class Study { public int ID { get; set; } public string Topic { get; set; } public byte TypeID { get; set; } public virtual StudyType Type { get; set; } public bool Deprecated { get; set; } public virtual ICollection<Study> Prerequisites { get; set; } } public class StudyType { public byte ID { get; set; } public string Name { get; set; } public virtual ICollection<Study> Studies { get;