String_agg 用于多列

我有以下选择

$repairs = DB::select(DB::raw('
            select r.id repair_id, w.name, w.surname
                from repairs r
                    join repair_worker rw on r.id = rw.repair_id
                    join workers w on w.id = rw.worker_id
                where r.vehicle_id = ?
                group by w.name, w.surname, r.id
           '),[$vehicle->id]);

我想得到w.name and w.surname到一个字段中，例如用逗号分隔。有一个功能string_agg(column, ',')但我没有运气让它发挥作用。我总是遇到语法错误。

My try:

$repairs = DB::select(DB::raw('
                select r.id repair_id, string_agg(w.name, w.surname, ', ') workers
                    from repairs r
                        join repair_worker rw on r.id = rw.repair_id
                        join workers w on w.id = rw.worker_id
                    where r.vehicle_id = ?
                    group by r.id
          '),[$vehicle->id]);

你会怎么做？

我正在使用最新的 Postgresql 9+

Use the ||运算符执行字符串连接，然后聚合此结果。

$repairs = DB::select(DB::raw("
    select r.id repair_id, string_agg(w.name || ' ' || w.surname, ', ') workers
    from repairs r
        join repair_worker rw on r.id = rw.repair_id
        join workers w on w.id = rw.worker_id
    where r.vehicle_id = ?
    group by r.id
    "),[$vehicle->id]);