摘要: 1)、临时表 select * from (select * from tb where id< 10) as B; select id, name, 1, (select count(1) from tb) from tb2 SELECT student_id, (select num from 阅读全文
posted @ 2020-01-13 21:52 四方游览 阅读(414) 评论(0) 推荐(0)