Laravel-eloquent技巧

1#获取别名

Hotel::query()
    ->where('city_id', $city_id)
    ->get(['hotel_name as name', 'id as value'])
    ->toArray();
//或者
Hotel::query()
    ->where('city_id', $city_id)
    ->select('hotel_name as name', 'id as value')
    ->toArray();

2#懒加载

Eloquent使用with懒加载必须通过$eloqumentModel->relationShip 获取到Collection而不是$eloqumentModel->relationShip()获取到hasOne或hasMany

Eloquent使用with的时候，get()获得的结果集是包含relationShip的Collections的，只有通过$eloqumentModel->relationShip才能正确的使用到懒加载机制

//正确写法
$roomTypeBasics = $item->hotel_rooms()
    ->with(['hotel_room_rate_plans'])
    ->get()
    ->filter(function (HotelRoom $xitem) {
        return $xitem->hotel_room_rate_plans->where("source", 1)->count() > 0;
    })
    //...
    
//错误写法
$roomTypeBasics = $item->hotel_rooms()
    ->with(['hotel_room_rate_plans'])
    ->get()
    ->filter(function (HotelRoom $xitem) {
        return $xitem->hotel_room_rate_plans()->where("source", 1)->count() > 0;
    })