将连接数组传递给laravel中的查询答案

【问题标题】：pass array of join to query in laravel将连接数组传递给laravel中的查询
【发布时间】：2019-04-18 11:44:50
【问题描述】：

我的查询有问题。我的示例查询如下

$answers = DB::table('IC2017_AY')
        ->join('IC2017', 'IC2017_AY.UNITID', '=', 'IC2017.UNITID')
        ->join('SFA1617_P1', 'IC2017_AY.UNITID', '=', 'SFA1617_P1.UNITID')
        ->join('cost', 'IC2017_AY.UNITID', '=', 'cost.UNITID')
        ->join('gpa', 'IC2017_AY.UNITID', '=', 'gpa.UNITID')
        ->join('enrollment', 'IC2017_AY.UNITID', '=', 'enrollment.UNITID')
        ->join('major', 'IC2017_AY.UNITID', '=', 'major.UNITID')
        ->join('preference', 'IC2017_AY.UNITID', '=', 'preference.UNITID')
        ->select('IC2017_AY.TUITION2 as in_state_tuition','IC2017_AY.FEE2 as in_state_fee','IC2017_AY.TUITION3 as out_state_tuition','IC2017_AY.FEE3 as out_state_fee','IC2017_AY.CHG4AY3 as books_supplies','IC2017_AY.CHG6AY3 as other_expenses','IC2017.ROOMAMT as room_charge','IC2017.BOARDAMT as board_charge','IC2017.RMBRDAMT as combined_charge','SFA1617_P1.SCUGRAD as total_receiving','SFA1617_P1.SCUGFFN as full_time_receiving','SFA1617_P1.UAGRNTN as total_receiving_grant')
        ->where($where_data);
        ->get();

但现在我想传递连接数组，因为连接将在运行时决定，如下所示下面的代码只是示例。

$joins = [
['country', 'user_master.country_id', '=', 'country.country_id'],
['city', 'user_master.city_id', '=', 'city.city_id'],
['login_master', 'user_master.user_id', '=', 
'login_master.user_id'],
];

我如何在 laravel 5.8 中做到这一点提前谢谢！

【问题讨论】：

标签： mysql sql laravel join

【解决方案1】：

您可以使用foreach loop 例如：

$joins = [
['country', 'user_master.country_id', '=', 'country.country_id'],
['city', 'user_master.city_id', '=', 'city.city_id'],
['login_master', 'user_master.user_id', '=', 
'login_master.user_id'],
];

$answers = DB::table('IC2017_AY')
        ->join('IC2017', 'IC2017_AY.UNITID', '=', 'IC2017.UNITID')
        ->join('SFA1617_P1', 'IC2017_AY.UNITID', '=', 'SFA1617_P1.UNITID')
        ->join('cost', 'IC2017_AY.UNITID', '=', 'cost.UNITID')
        ->join('gpa', 'IC2017_AY.UNITID', '=', 'gpa.UNITID')
        ->join('enrollment', 'IC2017_AY.UNITID', '=', 'enrollment.UNITID')
        ->join('major', 'IC2017_AY.UNITID', '=', 'major.UNITID')
        ->join('preference', 'IC2017_AY.UNITID', '=', 'preference.UNITID');

foreach($joins as $key=>$value){
$answer = $answer->join(implode(",",$value));
}

return $answer->select('IC2017_AY.TUITION2 as in_state_tuition','IC2017_AY.FEE2 as in_state_fee','IC2017_AY.TUITION3 as out_state_tuition','IC2017_AY.FEE3 as out_state_fee','IC2017_AY.CHG4AY3 as books_supplies','IC2017_AY.CHG6AY3 as other_expenses','IC2017.ROOMAMT as room_charge','IC2017.BOARDAMT as board_charge','IC2017.RMBRDAMT as combined_charge','SFA1617_P1.SCUGRAD as total_receiving','SFA1617_P1.SCUGFFN as full_time_receiving','SFA1617_P1.UAGRNTN as total_receiving_grant')
        ->where($where_data);
        ->get();

【讨论】：