Removing object mapping many to many relation in Entity Framework

Question

In ASP.NET MVC I have three tables: Users, Roles, UsersInRoles (standard many to many joining table). When I've mapped it to EF, it created two Entity Types: Users and Roles. Now I want to delete some user using code like below:

var aspnetUsers = _db.aspnet_Users.Single(a => a.UserId == id);
_db.aspnet_Users.DeleteObject(aspnetUsers);

of course I can't do it, because in SQL level in table UsersInRoles there is a connected row.

How to delete that row from EF level (UsersInRoles table is not mapped)?

Answer 1

You need to remove all the roles from the user object before calling SaveChanges() on the context:

var aspnetUser = _db.aspnet_Users.Single(a => a.UserId == id);

foreach(var role in aspnetUser.Roles.ToArray())
{
    aspnetUser.Roles.Remove(role);
}

_db.aspnet_Users.DeleteObject(aspnetUser);

_db.SaveChanges();

This will prevent the exception caused by the referential constraints in the database and ensure that the corresponding records in UsersInRoles table get deleted.