Laravel wherenotexists 返回 null

Question

I have the following piece of code

 $not_paid = Tenant::where('property_id', $property_id)
            ->whereNotExists(function ($query) use ($property_id) {
                $query->select('user_id')
                ->from('rent_paids'); 
            })
            ->get();

which is supposed to get all the tenants in a certain property, look them up in the rent_paids table and return the users who are not in the rent_paids table, as follows:

tenants table

Id	user_id	property_id
1	1	1
2	2	1
3	3	1

rent_paids

Id	user_id	property_id	amount_paid
1	1	1	3000

I want to be able to return the users in the tenants table and not in the rent_paids table. In this case, users 2 and 3 . But the above code returns an empty array.

Answer 1

You're missing the where clause to tie it back to the original table.

$not_paid = Tenant::where('property_id', $property_id)
        ->whereNotExists(function ($query) use ($property_id) {
            $query->select('user_id')
            ->from('rent_paids')
            ->whereColumn('tenants.user_id', '=', 'rent_paids.user_id'); 
        })
        ->get();