Laravel 联接子表中最新行的第一行

我有两张表

预订

和

港口移动

预订

有许多

港口移动

预订

列：

id，已关闭

port\u移动

列：

id、预订id、日期

如何返回

bookings

列表

where closed=false

并仅加入

bookings.id=port\u movements.booking\u id

上港口移动的1最新行以避免重复

这是我的密码

$query
->where('closed', false)
->join('port_movements as pm', 'bookings.id', '=', 'pm.booking_id')
->where(function ($q) {
       $q->where('pm.type', 'berthing')
         ->orWhere('pm.type', 'shifting');
})
->join('vessels', 'bookings.vessel_id', '=', 'vessels.id')
->join('berths', 'lm.berth_id', '=', 'berths.id')
->whereIn('berths.id', $berths);

---

我注意到您有

SQL

标记，所以我将用SQL解决方案来回答

如果不需要，请指定

laravel

并仅关联

问题是：

WITH newest_port_movements AS (
  SELECT
    booking_id
  , MAX("date") AS max_dt -- it is a reserved word, put in quotes
  FROM port_movements
  WHERE NOT closed
  GROUP BY booking_id
)
SELECT
  b.*
, pm.*
FROM bookings b
JOIN newest_port_movements npm
  ON b.id = npm.booking_id
 AND NOT b.closed
JOIN port_movements pm
  ON npm.booking_id = pm.booking_id
 AND npm.max_dt     = pm."date"
 AND NOT pm.closed
;

---

查询将是这样的

SELECT *
FROM bookings
         join port_movements as pm on pm.booking_id = bookings.id and
                                          pm.date = (SELECT MAX(date)
                                                         FROM port_movements
                                                         WHERE port_movements.booking_id = bookings.id)
where closed = false;

查询生成器

return DB::table('bookings')
            ->join('port_movements as pm', function ($join) {
                $join->on('pm.booking_id', '=', 'bookings.id');
                $join->on('pm.date', '=', DB::raw('(SELECT MAX(date) FROM port_movements WHERE port_movements.booking_id = bookings.id)'));
            })
            ->where('closed', false)
            ->get();

---

子查询部分不是我的最佳选择，可能有更好的方法来实现它。

如果是我，我会从sql开始