MySQL from型子查询

    把内层sql语句查询的结果作为临时表供外层sql语句再次查询.

    select goods_id, goods_name from goods where goods_id between 20 and 25;

    select goods_id, goods_name, cat_id from goods order by cat_id asc, goods_id desc;

    select goods_id, cat_id, goods_name from (select goods_id, goods_name, cat_id from goods order by cat_id asc, goods_id desc) as tmp group by cat_id;