Question

Is there an exact opposite action to ‘join‘ in linQ to SQL? I want to display just the results that do not fulfill the inner join constraint from a query. I wanna do it just in one query. Here’s an example of it’s use (http://img165.imageshack.us/img165/4940/liststj3.jpg).

Answer 1

Falvarez’s roles:

Roles.Where(r => r.Users.Any(u => u.Name == 'falvarez')); 

Roles that falvarez doesn’t have

Roles.Where(r => !r.Users.Any(u => u.Name == 'falvarez')); 

Project each role into an object that knows whether falvarez is in that role

Roles.Select(r => new   {     FalvarezInRole = r.Users.Any(u => u.Name == 'falvarez'),     Role = r   }); 

In the case that the role object doesn’t have a users property, simply substitute a query that filters users by role in the place of r.Users