在控制器中查询雄辩结果为空，为什么？

Question

$rooms3 = Room::join("notifications", "notifications.room_id", "rooms.id")
            ->where('rooms.user_id', Auth::user()->id)
            ->join("watt_histories", "watt_histories.notification_id", "notifications.id")
            ->where('notifications.id', 'watt_histories.notification_id')
            ->latest('watt_histories.created_at')
            ->first();

如果查询运行良好，则返回的值不为空

Answer 1

如果您打算比较表之间的 ID，则可能应该是 where('notifications.id', '=', 'watt_histories.notification_id') 或类似的，假设 notification.id 和 watt_histories.notification_id 是需要匹配即可查询成功。

$rooms3 = Room::join("notifications", "notifications.room_id", "rooms.id")
    ->where('rooms.user_id', Auth::user()->id)
    ->join("watt_histories", "watt_histories.notification_id", "notifications.id")
    ->where('notifications.id', '=', 'watt_histories.notification_id') // Corrected the comparison here
    ->latest('watt_histories.created_at')
    ->first();