如何查询以找到laravel 5的出发和到达时间？

Question

我试图搜索发车时间和公交车到达时间

我的数据库

id | bus_id | city | time
1  |1       |  1   | 05:00
2  |1       |  2   | 06:00
3  |1       |  3   | 07:00

示例用户选择城市起点= 1，城市目的地= 2

那我期望的结果是

bus | time departure | time arrival
1   | 05:00          | 06:00

我的查询

$departures = Departure::whereBetween(
    'city', [
        $request->origin, $request->destination
    ])
->get();

Answer 1

如果特定公交车到达特定城市的时间仅为一个记录， 您可以尝试执行此操作，否则它将返回最大到达时间和最大离开时间。

它将两个记录合并在一起（从bus_1到A，从bus_1到b），然后选择最大时间作为到达时间或离开时间：

$departure_citys = Departure::where('city',$request->origin)
                           ->selectRaw('id, 
                                        bus_id, 
                                        city,
                                        time AS time_departure, 
                                        NULL AS time_arrival');

$arrival_citys   = Departure::where('city',$request->destination)
                           ->selectRaw('id, 
                                        bus_id, 
                                        city,
                                        NULL AS time_departure, 
                                        time AS time_arrival');

$departures = $departure_citys->unionAll($arrival_citys);

DB::table(DB::raw("({$departures->toSql()}) AS tr"))
                              ->mergeBindings($departures->getQuery())
                              ->groupBy('city')
                              ->selectRaw('bus_id,
                                          MAX(time_departure) AS time_dept,
                                          MAX(time_arrival) AS time_arvl')->get();