Question

我在我雄辩的模型中有以下范围，我想为它添加两个条件。这样做我需要帮助。

public function scopeImages($query) {
    $query->join('images as i', function ($join) {
        $join->on('i.vessel_id', '=', 'vessel.id')
        ->where('i.sort', '=', 'min(i.sort)');
    })
    ->leftjoin('users', 'users.id', '=', 'vessel.user_id')
    ->select('vessel.*', 'i.image as image', 'users.name as brokername');
}

images表包含featured和sort列。我想选择返回结果的images.featured is 1和min sort的一行。如果没有images.featured=1，那么我想选择min of sort。

目前，上述范围为每个min sort

选择vessel_id的图片

Answer 1

如果您在desc中按特色（如果特色是布尔值）订购并在asc中排序，它将列出最高优先级的特色1，然后列出从最小到最大的排序。现在，如果你采取第一行，你将得到你想要的。

$query->join('images', 'images.vessel_id', '=', 'vessel.id')
        ->leftjoin('users', 'users.id' ,'=', 'vessel.user_id')
        ->select('vessel.*', 'images.image as image', 'users.name as brokername')
        ->orderBy('images.featured', 'DESC')
        ->orderBy('images.sort', 'ASC')
        ->take(1);

Answer 2

您需要一个相关的子查询

https://dev.mysql.com/doc/refman/5.5/en/correlated-subqueries.html

    SELECT  v.*, 
(SELECT `image` FROM images WHERE vessel_id = v.id ORDER BY featured DESC, sort LIMIT 1) AS image
    FROM `vessel` AS v

@EDIT 你可以尝试一下：

public function scopeImages($query) {
    return $query
        ->leftjoin('users', 'users.id', '=', 'vessel.user_id')
        ->select(\DB::raw("vessel.*, (SELECT `image` FROM images WHERE vessel_id = vessel.id ORDER BY featured DESC, sort LIMIT 1) AS image, users.name as brokername"));
}

条件表连接

2 个答案: