我想从表中检索随机行,但这些行必须按类别排序。
select category,
(select order_number
from orders
where order_number in (123,125,128,129,256,263,966,258,264,159,786)
order by rand())
from orders
order by category
这是我尝试过的查询。但这会检索表中的整个数据。
工作查询;
SELECT category,order_number FROM (
SELECT category,order_number
from orders
where order_number in (`$order_numbers_variable`)
order by rand()
) order by category