select [user].[name],
(select [name] from content where userid=[user].id),
(select [name] from config where id in (select configID from content where userid=[user].id)) from [user]
(select [name] from content where userid=[user].id),
(select [name] from config where id in (select configID from content where userid=[user].id)) from [user]
a ok null
b null null
c null null
left join content c on c.id=a.id order by a.name