Laravel Eloquent LEFT JOIN WHERE NULL

问题描述

我正在尝试使用 Eloquent 在数据库种子期间执行以下查询:

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

这是我在 Eloquent 中的实现:

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();

第一个查询总是返回完整的结果，而 Eloquent 的等效项总是返回空元素，除了 customers 的 email 和 phone 字段> 桌子.我无法解释这一点，因为 Customers 和 Orders 模型都是工匠生成的骨架.

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.

例如:

class Customer extends Eloquent {

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

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

}

这是当我 dd() 对种子(最初由 Faker 生成)第一个 Eloquent 查询时输出的数组:

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) "luther.braun@example.org"
    '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
}

推荐答案

这可以通过指定特定表中所需的特定列名来解决，如下所示:

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'
    ]);

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