MVC4 Code first approach, how to fix the following? - entity-framework

Question

I am getting the following error
One or more validation errors were detected during model generation:
\tSystem.Data.Entity.Edm.EdmAssociationEnd: : Multiplicity is not valid in Role 'UserRoles_Roles_Source' in relationship 'UserRoles_Roles'. Because the Dependent Role refers to the key properties, the upper bound of the multiplicity of the Dependent Role must be '1'.
My entities and the associated mappings are defined as follows,
public class UserProfile
{
public UserProfile()
{
UserUserRoles = new List<UserRoles>();
}
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string UserName { get; set; }
public virtual ICollection<UserRoles> UserUserRoles { get; set; }
}
public class Roles
{
public Roles()
{
RoleUserRoles = new List<UserRoles>();
}
public int RoleId { get; set; }
public string RoleName { get; set; }
public virtual ICollection<UserRoles> RoleUserRoles { get; set; }
}
public class UserRoles
{
public int UserId { get; set; }
public int RoleId { get; set; }
public virtual UserProfile User { get; set; }
public virtual Roles Roles { get; set; }
}
//Mappings
public UserProfileMap()
{
// Primary Key
HasKey(t => t.UserId);
// Properties
Property(t => t.UserName)
.HasMaxLength(56);
// Table & Column Mappings
ToTable("UserProfile");
Property(t => t.UserId).HasColumnName("UserId");
Property(t => t.UserName).HasColumnName("UserName");
}
public class RolesMap : EntityTypeConfiguration<Roles>
{
public RolesMap()
{
// Primary Key
HasKey(t => t.RoleId);
// Properties
Property(t => t.RoleName)
.HasMaxLength(256);
// Table & Column Mappings
ToTable("webpages_Roles");
Property(t => t.RoleId).HasColumnName("RoleId");
Property(t => t.RoleName).HasColumnName("RoleName");
}
}
public class UserRolesMap : EntityTypeConfiguration<UserRoles>
{
public UserRolesMap()
{
// Primary Key
HasKey(t => t.UserId);
HasKey(t => t.RoleId);
// Table & Column Mappings
ToTable("webpages_UsersInRoles");
Property(t => t.UserId).HasColumnName("UserId");
Property(t => t.RoleId).HasColumnName("RoleId");
// Relationships
HasRequired(t => t.User)
.WithMany(t => t.UserUserRoles)
.HasForeignKey(d => d.UserId);
HasRequired(t => t.Roles)
.WithMany(t => t.RoleUserRoles)
.HasForeignKey(d => d.RoleId);
}
}
what am I doing wrong?

Answer 1

Per the comments:
A combined primary key should be constructed as HasKey(t => new { t.UserId, t.RoleId });

Answer 2

It looks like you want to create a many-to-many relation between models. In that case you do not need the class UserRoles, it will be generated by EF when using this scenario:
public class User
{
// other properties
public virtual IList<Role> Roles {get;set;}
}
public class Role
{
// other properties
public virtual IList<User> Users {get;set;}
}
However, if you do want the UserRoles model to for instance store additional information you need to make the mapping manually in for example the OnModelCreating() function of the DbContext class.