Laravel查询构建器连接多个子查询

$subquery1 = DB::table('table1')
                ->select('column1')
                ->where('column2', '=', 'value');

$subquery2 = DB::table('table2')
                ->select('column3')
                ->where('column4', '>', 'value');

$query = DB::table('main_table')
            ->select('column5')
            ->joinSub($subquery1, 'alias1', function ($join) {
                $join->on('main_table.column6', '=', 'alias1.column1');
            })
            ->joinSub($subquery2, 'alias2', function ($join) {
                $join->on('main_table.column7', '=', 'alias2.column3');
            })
            ->get();