Code First Entity Framework中的Seed方法未填充多对多关系中的链接表

Question

I am new to entity framework code first. I am trying to create a many-to-many relationship between User and Role. The link table will be UserRole. The following is my code:

public class User
    {
        public int UserId { get; set; }

    [Required]
        [MaxLength(100)]

    public string Username { get; set; }

    [Required]
        [MaxLength(100)]

    public string Email { get; set; }

    public string HashedPassword { get; set; }

    public string Salt { get; set; }

    public bool IsLocked { get; set; }

    public DateTime DateCreated { get; set; }

        public virtual ICollection<Role> Roles { get; set; }

    }

public class Role
    {
        public int RoleId { get; set; }
        public string RoleName { get; set; }

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

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
{
    modelBuilder.Entity<User>()
            .HasMany(r => r.Roles)
            .WithMany(u => u.Users)
            .Map(ur =>
            {
                ur.MapLeftKey("UserId");
                ur.MapRightKey("RoleId");
                ur.ToTable("UserRole");
            }
        );
}

protected override void Seed(LabRating.Data.LabRatingContext context)
    {
    context.UserSet.AddOrUpdate(u => u.Email, new User[]{

    new User()
            {
                Email = "abc.blog@gmail.com",

        Username = "abc123",

        HashedPassword = "XwAQoiq84p1RUzhAyPfaMDKVgSwnn80NCtsE8dNv3XI=",

        Salt = "mNKLRbEFCH8y1xIyTXP4qA==",

                IsLocked = false,

                DateCreated = DateTime.Now

    }
        });

    context.RoleSet.AddOrUpdate(new Role[] {
            new Role()
            {
                RoleName= "Admin"
             }
            });
}

As you can see first I am creating the two tables -User and Role - and then I am establishing the many-to-many relationship using Fluent API in the OnModelCreating method. When I checked the database, I see all three tables - User, Role and UserRole - being created correctly. When the Seed method is run, only the User and Role tables are populated with the data shown above but not the UserRole table. Please let me know how to resolve this issue.

Answer 1

protected override void Seed(DatabaseContext context)
{
    Role role = new Role
    {
        RoleName = "Admin"
    };
    Role role2 = new Role
    {
        RoleName = "HR"
    };
    Role role3 = new Role
    {
        RoleName = "Marketing"
    };

    var roles= new List<Role> { role, role2,role3 };
    roles.ForEach(i => context.Roles.AddOrUpdate(i));
    context.SaveChanges();

    User user= new User
    { 
        Email = "abc.blog@gmail.com",
        Username = "abc123",
        HashedPassword = "XwAQoiq84p1RUzhAyPfaMDKVgSwnn80NCtsE8dNv3XI=",
        Salt = "mNKLRbEFCH8y1xIyTXP4qA==",
        IsLocked = false,
        DateCreated = DateTime.Now,
        Roles= new List<Role> { role,role2 }
    };

    User user2 = new User
    { 
        Email = "def.blog@gmail.com",
        Username = "def123",
        HashedPassword = "XwAQoiq84p1RUzhAyPfaMDKVgSwnn80NCtsE8dNv3XI=",
        Salt = "mNKLRbEFCH8y1xIyTXP4qA==",
        IsLocked = false,
        DateCreated = DateTime.Now,
        Roles= new List<Role> { role3 }
    };

    var users= new List<User> { user, user2};
    users.ForEach(a => context.Users.AddOrUpdate(a));
    context.SaveChanges();
}