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

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");               
    }
}