public void Remove_SubEntity_Detached()
{
User userWithGroups;
using (var context = new MeetupContext())
{
var tmpUser = _context.Users
.Include(x => x.Groups)
.ThenInclude(x => x.Group)
.First(x => x.Id == 1);
tmpUser.Groups.Add(new UserGroup {
UserId = tmpUser.Id, GroupId = 1
});
context.SaveChanges();
userWithGroups = _context.Users
.Include(x => x.Groups)
.ThenInclude(x => x.Group)
.First(x => x.Id == 1);
}
var group = userWithGroups.Groups.FirstOrDefault();
userWithGroups.Groups.Remove(group);
_context.Attach(userWithGroups);
_context.SaveChanges();
}