navigation-properties | 易学教程

Navigation Properties as Primary Keys

阅读更多关于 Navigation Properties as Primary Keys

问题 I'm using EF 6 with MVC 5. I have a class defined as follows: public class ConEdSignup { [Key, Column(Order = 0)] public virtual ApplicationUser Attendee { get; set; } [Key, Column(Order = 1)] public virtual ConEdSession ConEdSession { get; set; } [Required] public DateTime SignupTime { get; set; } [Required] public bool Attended { get; set; } } This is basically a link table for a many-to-many relationship where I have additional properties about that relationship. When I try to create a

Using navigation properties in entity framework code first

阅读更多关于 Using navigation properties in entity framework code first

问题 Context: Code First, Entity Framework 4.3.1; User ---- Topic, 1 to Many relation; User with public virtual ICollection<Topic> CreatedTopics Navigation Property(Lazy Loading); Topic with public virtual User Creator Navigation Property; DataServiceController : DbDataController<DefaultDbContext> , Web API beta, ASP.NET MVC 4 Beta , Single Page Application; System.Json for Json serialization; Web API Action: public IQueryable<Topic> GetTopics() { // return DbContext.Topics; // OK return DbContext

Can I lazy load a navigation property by delegating to a stored procedure in EF?

阅读更多关于 Can I lazy load a navigation property by delegating to a stored procedure in EF?

问题 I have the following customer class: public class Customer { public long Id { get; set; } public virtual ICollection<Order> Orders { get; set; } } My database has Customers and Orders tables, but no foreign key relationships. Orders for a customer are obtained using a stored procedure that takes the customer ID and returns the order rows. I can't modify the database. I know how to call the stored procedure from Entity Framework, but, is it possible to configure the DbContext using the fluent

Ignore Properties in OnModelCreating

阅读更多关于 Ignore Properties in OnModelCreating

问题 I'm attempting to use Bounded (Db) Contexts in Entity Framework 5.0, and I'm having problems excluding a property from one of the classes included in a specific context. Here is the information (I'll shorten for brevity) BaseContext.cs public class BaseContext<TContext> : DbContext where TContext : DbContext { static BaseContext() { Database.SetInitializer<TContext>(null); } protected BaseContext() : base("name=Development") { } } IContext.cs public interface IContext : IDisposable { int

Can I lazy load a navigation property by delegating to a stored procedure in EF?

阅读更多关于 Can I lazy load a navigation property by delegating to a stored procedure in EF?

I have the following customer class: public class Customer { public long Id { get; set; } public virtual ICollection<Order> Orders { get; set; } } My database has Customers and Orders tables, but no foreign key relationships. Orders for a customer are obtained using a stored procedure that takes the customer ID and returns the order rows. I can't modify the database. I know how to call the stored procedure from Entity Framework, but, is it possible to configure the DbContext using the fluent API so that accessing the Orders collection of a customer object would lazy load the entities via a

Entity Framework Core: private or protected navigation properties

阅读更多关于 Entity Framework Core: private or protected navigation properties

Is it somehow possible to define navigation properties in EFCore with private or protected access level to make this kind of code work: class Model { public int Id { get; set; } virtual protected ICollection<ChildModel> childs { get; set; } } You have two options, using type/string inside the model builder. modelBuilder.Entity<Model>(c => c.HasMany(typeof(Model), "childs") .WithOne("parent") .HasForeignKey("elementID"); ); Not 100% sure it works with private properties, but it should. Update: Refactoring-safe version modelBuilder.Entity<Model>(c => c.HasMany(typeof(Model), nameof(Model.childs)

Including navigation properties from Entity Framework TPH classes

阅读更多关于 Including navigation properties from Entity Framework TPH classes

问题 I've got an EF hierarchy that (dramatically simplified) looks something like this: class Room { EntityCollection<Session> Sessions; } class Session { EntityCollection<Whiteboard> Whiteboards; EntityReference Room; } class Whiteboard { EntityCollection<WhiteboardShape> WhiteboardShapes; EntityReference Session; } abstract class WhiteboardShape { EntityReference Whiteboard; } class WhiteboardShapeEllipse : WhiteboardShape { } class WhiteboardShapePolyline { WhiteboardShape { EntityCollection

Ignore Properties in OnModelCreating

阅读更多关于 Ignore Properties in OnModelCreating

I'm attempting to use Bounded (Db) Contexts in Entity Framework 5.0, and I'm having problems excluding a property from one of the classes included in a specific context. Here is the information (I'll shorten for brevity) BaseContext.cs public class BaseContext<TContext> : DbContext where TContext : DbContext { static BaseContext() { Database.SetInitializer<TContext>(null); } protected BaseContext() : base("name=Development") { } } IContext.cs public interface IContext : IDisposable { int SaveChanges(); void SetModified(object entity); void SetAdded(object entity); } ISuiteContext.cs public

Can you exclude reverse navigation properties in EF when eager loading?

阅读更多关于 Can you exclude reverse navigation properties in EF when eager loading?

问题 When I use the .Include syntax in EF6, reverse navigation properties are always loaded. Is there a way to turn that off? Here is a sample query. private static IQueryable<Account> GetAccountsEager(this IRepository<Account> repository) { return repository .Queryable() .Include(e => e.AccountLocations .Select(l => l.Address.City.State.Country)); } This gives me the account's collection of AccountLocations. However, the Address' city has this reverse navigation property on it: public virtual

Entity Framework (Database-First) multiple relations to same table naming conventions control

阅读更多关于 Entity Framework (Database-First) multiple relations to same table naming conventions control

Let's suppose that we have this situation: Tables in database: Country (id, country_name), Person (id, login), CountryManager (id_country, id_person), CountryStakeholder (id_country, id_person) If we had to create the model from the database, using Entity Framework Database-First, in VS we'd have a class like this: class Country { int id; string country_name; virtual ICollection<Person> Person1; // Navigation Properties virtual ICollection<Person> Person2; // ---------||---------- } I've simplified the code a lot, but hopefully you got the point. Seems that when Entity Framework deals with