Laravel withCount（）返回null

Question

I need to count the results of Many-to-Many relation subquery.

return $q->withCount(['users' => function($q) {
    $q->select("Users.Id as Id_user","Users.Name");
}])->get()

This code doesn't work. It return null.

However, that works fine and successfully adds users_count column:

return $q->withCount(['users'])->get();

But I need to make select subquery to select specific columns from the relation so I need my first variant get to work.

Thanks a lot!

Answer 1

when you use Count or withCount method, the query builder does a select count(id) as aggregate

if in the condition par of the withCount you override the select part. it breaks

return $q->withCount(['users' => function($q) {
    //here you are supposed to do condition, not a select
    $q->select("Users.Id as Id_user","Users.Name");
}])->get()

if you want the id and the name of the user, use with

return $q->withCount(['users'])
    ->with(['users' => function($q) {
        $q->select("Users.Id as Id_user","Users.Name");
    }])
    ->get()