如何从Laravel 5中的集合中获取物品？

Question

我是新手，Laravel无法弄清楚如何从返回的集合中获取项目的值。这是我的代码：

$aircraft = Aircraft::join('pams_shared.shared_aircraft', 'aircraft.shared_aircraft_id', '=', 'pams_shared.shared_aircraft.shared_aircraft_id')
        ->select('aircraft.*', 'shared_aircraft.*')
        ->where('aircraft.owner_id',Auth::user()->owner_id)
        ->where('registration',$reg)
        ->get();

我想从中获取价值，aircraft.aircraft_id但这就是我遇到的问题。我试过了：

    $id = $aircraft->aircraft_id;

我试过了：

    $id = $aircraft->aircraft.aircraft_id;

我也尝试过：

    $id = array_get($aircraft, 'aircraft_id');

但是我得到null了一种价值。当我执行var_dump($aircraft)或时，dd($aircraft)我可以确认数据在那里。

在我看来，我可以通过循环访问该值，但是我需要控制器中的数据才能对另一个表执行第二次查询。

希望有道理。干杯。

编辑

运行时，dd($aircraft);我得到以下信息：

Collection {#239 ?
#items: array:1 [?
    0 => Aircraft {#240 ?
            #fillable: array:8 [?]
            #table: "aircraft"
            #primaryKey: "aircraft_id"
            #connection: null
            #perPage: 15
            +incrementing: true
            +timestamps: true
            #attributes: array:16 [?
                "aircraft_id" => 5
                "owner_id" => 2
                "shared_aircraft_id" => 67443
                "year" => 2012
                "serial_number" => "C127RG3"
                "registration" => "C-SMTH"
                "created_by" => 2
                "modified_by" => 2
                "created_at" => "0000-00-00 00:00:00"
                "updated_at" => "0000-00-00 00:00:00"
                "aircraft_code" => "2072438"
                "aircraft_mfr" => "CESSNA"
                "aircraft_model" => "172RG"
                "aircraft_type" => 4
                "aircraft_eng" => 1
                "aircraft_cat" => 1
                ]
            #original: array:16 [?]
            #relations: []
            #hidden: []
            #visible: []
            #appends: []
            #guarded: array:1 [?]
            #dates: []
            #casts: []
            #touches: []
            #observables: []
            #with: []
            #morphClass: null
            +exists: true
        }
    ]
}

Answer 1

在上使用get()method时，query builder无论获得多少记录，它都会返回一个数组。因此，您可以通过按索引指向它来访问它。顺便说一句，不要忘记检查是否为空以克服可能的错误。

$id = 0;
$aircraft = Aircraft::join('pams_shared.shared_aircraft', 'aircraft.shared_aircraft_id', '=', 'pams_shared.shared_aircraft.shared_aircraft_id')
        ->select('aircraft.*', 'shared_aircraft.*')
        ->where('aircraft.owner_id',Auth::user()->owner_id)
        ->where('registration',$reg)
        ->get();
// now you can access properties
if(count($aircraft) > 0) $id = $aircraft[0]->aircraft_id;

Answer 2

如果您执行查询，get()您将始终得到一个集合作为结果。即使您只需要一种型号。改变它的最简单方法是使用first()：

$aircraft = Aircraft::join('pams_shared.shared_aircraft', 'aircraft.shared_aircraft_id', '=', 'pams_shared.shared_aircraft.shared_aircraft_id')
    ->select('aircraft.*', 'shared_aircraft.*')
    ->where('aircraft.owner_id',Auth::user()->owner_id)
    ->where('registration',$reg)
    ->first();

$id = $aircraft->aircraft_id;