帶有查詢生成器的 Laravel 子查詢

Question

我有一個這樣的 MySQL 查詢：

SELECT
    a.id,
    a.nip,
    a.name,
    COUNT(
      (
        SELECT id
        FROM covis_transactions
        WHERE user_id = a.id
      )
    ) AS total_survey
FROM users a
WHERE a.user_role_id = 7
GROUP BY a.id

我嘗試將其轉換為 Eloquent 查詢，但這似乎不起作用：

DB::table('users as a')
    ->selectRaw("a.id, a.nip, a.name, COUNT(".DB::table('covis_transactions')->where('user_id', 'a.id').") as total_survey")
    ->where('a.user_role_id', 7)
    ->groupBy('a.id')
    ->get();

Answer 1

您應該在您的User模型和covis_transactions表的模型之間創建關系。 （我將其稱為CovisTransaction ）

# User.php
public function covis_transactions()
{
    return $this->hasMany(CovisTransaction::class);
}

然后，您可以使用withCount來獲取聚合計數。

User::query()
    ->select('id', 'nip', 'name')
    ->withCount('covis_transactions as total_survey')
    ->where('user_role_id', 7)
    ->groupBy('id')
    ->get();

---

• https://laravel.com/docs/9.x/eloquent-relationships#one-to-many
• https://laravel.com/docs/9.x/eloquent-relationships#aggregating-related-models

Answer 2

您可以將子查詢從構建器轉換為字符串：

DB::table('covis_transactions')->where('user_id', 'a.id')

DB::table('covis_transactions')->where('user_id', 'a.id')->toSql()

試試看 ：

DB::table('users as a')
            ->selectRaw("a.id, a.nip, a.name, COUNT(" . DB::table('covis_transactions')->where('user_id', 'a.id')->toSql() . ") as total_survey")
            ->where('a.user_role_id', 7)
            ->groupBy('a.id')
            ->get();

或者可以使用join然后 count( covis_transactions . id )