(1) select user_id,ord_id,create_time
(2) from table_b
(3) where ds='20200630'
(4) order by create_time
(5) limit 20;
(1)(2)(3)(4)(5)
(2)(3)(1)(4)(5)
(2)(1)(3)(4)(5)
(2)(3)(4)(1)(5)
