php - Laravel 5.3 中三个表的 sql 连接

Question

我想在 laravel 5.3 中联接三个表。我想联接三个表并获取审批者姓名和部门名称

table travel_request
id
approver_id (fk)
department_id (FK) 

user table
approver_id
name

Department table
department_id 
dept_name

query
 $users = DB::table('travel_request')
        ->join('department', 'travel_request.department_id', '=', 'department.department_id')
        ->join('users', 'travel_request.department_id', '=', 'users.approver_id')
        ->select('travel_request.*', 'department.name as dept_name','users.name as approver_name')->get();

Answer 1

您使用 ->join('users', 'travel_request.department_id', '=', 'users.approver_id')

应该是

$users = DB::table('travel_request')
    ->join('department', 'travel_request.department_id', '=', 'department.department_id')
    ->join('users', 'travel_request.approver_id', '=', 'users.approver_id')
    ->select('travel_request.*', 'department.name as dept_name','users.name as approver_name')->get();