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php – Laravel Eloquent LEFT JOIN WHERE NULL

Posted by: admin April 23, 2020 Leave a comment

Questions:

I’m trying to use Eloquent to perform the following query during a database seed:

SELECT
    *
FROM
    customers
LEFT JOIN
    orders
    ON customers.id = orders.customer_id
WHERE
    orders.customer_id IS NULL

And here is my implementation in Eloquent:

$c = Customer::leftJoin('orders', function($join) {
      $join->on('customers.id', '=', 'orders.customer_id');
    })
    ->whereNull('orders.customer_id')
    ->first();

Whereas the first query always returns full results, the Eloquent equivalent always returns empty elements for everything but the email and phone fields of the customers table. I’m at a loss to explain this since the Customers and Orders models are both artisan generated skeletons.

Ex:

class Customer extends \Eloquent {

    // Add your validation rules here
    public static $rules = [
        // 'title' => 'required'
    ];

    // Don't forget to fill this array
    protected $fillable = [];

}

Here is the array that is output when I dd() the first Eloquent query on a seed (generated originally by Faker):

protected $original =>
  array(25) {
    'id' =>
    NULL
    'first_name' =>
    NULL
    'last_name' =>
    NULL
    'email' =>
    string(24) "[email protected]"
    'phone' =>
    string(17) "642.150.9176x5684"
    'address1' =>
    NULL
    'address2' =>
    NULL
    'city' =>
    NULL
    'state' =>
    NULL
    'county' =>
    NULL
    'district' =>
    NULL
    'postal_code' =>
    NULL
    'country' =>
    NULL
    'notes' =>
    NULL
    'created_at' =>
    NULL
    'updated_at' =>
    NULL
    'customer_id' =>
    NULL
    'total' =>
    NULL
}
How to&Answers:

This can be resolved by specifying the specific column names desired from the specific table like so:

$c = Customer::leftJoin('orders', function($join) {
      $join->on('customers.id', '=', 'orders.customer_id');
    })
    ->whereNull('orders.customer_id')
    ->first([
        'customers.id',
        'customers.first_name',
        'customers.last_name',
        'customers.email',
        'customers.phone',
        'customers.address1',
        'customers.address2',
        'customers.city',
        'customers.state',
        'customers.county',
        'customers.district',
        'customers.postal_code',
        'customers.country'
    ]);

Answer:

You can also specify the columns in a select like so:

$c = Customer::select('*', DB::raw('customers.id AS id, customers.first_name AS first_name, customers.last_name AS last_name'))
->leftJoin('orders', function($join) {
  $join->on('customers.id', '=', 'orders.customer_id') 
})->whereNull('orders.customer_id')->first();

Answer:

I would dump your query so you can take a look at the SQL that was actually executed and see how that differs from what you wrote.

You should be able to do that with the following code:

$queries = DB::getQueryLog();
$last_query = end($queries);
var_dump($last_query);
die();

Hopefully that should give you enough information to allow you to figure out what’s gone wrong.

Answer:

I would be using laravel whereDoesntHave to achieve this.

Customer::whereDoesntHave('orders')->get();

Answer:

Although above versions work well, i want to give you alternate short version which i use very often:

Customer::select('customers.*')
        ->leftJoin('orders', 'customers.id', '=', 'orders.customer_id')
        ->whereNull('orders.customer_id')->first();