many to many relation in asp.net mvc EF code first - asp.net-mvc

Question

I'm using asp.net mvc 4, EF, codefirst to make a many to many relation to a users and roles system
the user model:
public class User
{
#region properties
[Key]
public Int32 Id { get; set; }
[Required]
public String UserName { get; set; }
public String Password { get; set; }
[Required]
public String Email { get; set; }
public DateTime CreationDate { get; set; }
public DateTime LastUpdate { get; set; }
public DateTime? LastLogin { get; set; }
[ForeignKey("RoleId")]
public virtual ICollection<Role> Roles { get; set; }
#endregion //properties
#region constructors
public User()
{
Roles = new HashSet<Role>();
LastUpdate = DateTime.Now;
CreationDate = DateTime.Now;
}
#endregion //constuctors
}
the role model:
public class Role
{
[Key]
public Int32 Id { get; set; }
public String Name { get; set; }
public String Description { get; set; }
public DateTime CreationDate { get; set; }
public DateTime LastUpdate { get; set; }
[ForeignKey("UserId")]
public virtual ICollection<User> Users { get; set; }
public Role()
{
Users = new HashSet<User>();
CreationDate = DateTime.Now;
LastUpdate = DateTime.Now;
}
}
the context:
public class UserManagementContext : Context, IContext
{
public DbSet<User> Users { get; set; }
public DbSet<Role> Roles { get; set; }
public UserManagementContext() {
Database.SetInitializer<UserManagementContext>(null);
}
void IContext.Setup(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().ToTable("Users");
modelBuilder.Entity<Role>().ToTable("Roles");
modelBuilder.Entity<User>()
.HasMany(u => u.Roles)
.WithMany(r => r.Users)
.Map(
m =>
{
m.MapLeftKey("UserId");
m.MapRightKey("RoleId");
m.ToTable("UserRoles");
});
}
}
When the database tables are generated the tables users, roles and userroles are there. Then I make a record in users, one in roles and one in userroles to connect those. The userroles table has two columns RoleId and UserId.
Then I try to load the roles of a user like this:
public String[] GetRoles(String userName)
{
//var user = ConcreteContext.Users.Include("Roles").Where(u => u.UserName == userName).FirstOrDefault();
var users = ConcreteContext.Users.Include(u => u.Roles);
var user = users.FirstOrDefault();
var roles = from r in user.Roles
select r.Name;
return roles.ToArray();
}
But the line with var users = ConcreteContext.Users.Include(u => u.Roles); raises the next error:
System.Data.SqlClient.SqlException: Invalid object name 'dbo.RoleUsers'.
If I change de table name of UserRoles to RoleUsers when de database is created (by using m.ToTable(RoleUsers) ), I get a lot of different errors about wrong field names.
Anyone an idea what I'm missing here?
Thanks in advance,
Willem

Answer 1

Any reason why you have to use the Fluent API?
You can map Many-to-many like this with data attributes:
public class User
{
[InverseProperty( "Users" )]
public virtual ICollection<Role> Roles {get;set;}
}
public class Role
{
[InverseProperty( "Roles" )]
public virtual ICollection<User> Users {get;set;}
}

Answer 2

This will do what I needed:
public class User
{
#region properties
[Key]
public Int32 Id { get; set; }
[Required]
public String UserName { get; set; }
public String Password { get; set; }
[Required]
public String Email { get; set; }
public DateTime CreationDate { get; set; }
public DateTime LastUpdate { get; set; }
public DateTime? LastLogin { get; set; }
[InverseProperty("Users")]
public virtual ICollection<Role> Roles { get; set; }
#endregion //properties
#region constructors
public User()
{
LastUpdate = DateTime.Now;
CreationDate = DateTime.Now;
}
#endregion //constuctors
}
public class Role
{
[Key]
public Int32 Id { get; set; }
public String Name { get; set; }
public String Description { get; set; }
public DateTime CreationDate { get; set; }
public DateTime LastUpdate { get; set; }
[InverseProperty("Roles")]
public virtual ICollection<User> Users { get; set; }
public Role()
{
CreationDate = DateTime.Now;
LastUpdate = DateTime.Now;
}
}
public class UserManagementContext : Context, IContext
{
public DbSet<User> Users { get; set; }
public DbSet<Role> Roles { get; set; }
public UserManagementContext() {
Database.SetInitializer<UserManagementContext>(null);
}
void IContext.Setup(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().ToTable("Users");
modelBuilder.Entity<Role>().ToTable("Roles");
}
}