如何使用组合主键在存储库模式工作实体框架单元中插入/删除记录

Question

I have a following table with only two column with combined primary key

Table Name : ProductByUser

Column 1 : ProductId (FK Ref. to Product Table)

Column 2 : UserId (FK Ref. to User Table)

Additional Information: In edmx also I am not able to view this table but it show direct relationship between Product & User Table.

I am not able to make out how to delete or Insert record into this table. As I am not directly able to create an object of this table. So kindly guide me on the same.

Answer 1

Try this:

public class ProductByUser // Many to many table implemented as entity
{
    public int ProductId  { get; set; }
    public int UserId  { get; set; }

    public virtual ICollection<Product> Products { get; set; }
    public virtual ICollection<User> Users { get; set; }
}


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
   modelBuilder.Entity<ProductByUser>()
       .HasKey(c => new { c.ProductId , c.UserId });

   modelBuilder.Entity<Product>()
       .HasMany(c => c.ProductUsers)
       .WithRequired()
       .HasForeignKey(c => c.ProductId);

   modelBuilder.Entity<User>()
       .HasMany(c => c.ProductUsers)
       .WithRequired()
       .HasForeignKey(c => c.UserId);  
}

Answer 2

Finally got the way out , Hope this will help some one in future,

 void Insert(Product product, int intUserId)
  {
     _unitofWork.Db.Entry(product).Collection(i => i.Users).Load();

      UserRepository userRepo = new UserRepository(_unitofWork);

     product.Users.Add(userRepo.GetAll().FirstOrDefault(U => U.UserID == intUserId));

  }

For deleting

 product.Users.Remove(userRepo.GetAll().FirstOrDefault(U => U.UserID == intUserId));