在Oracle中写子查询，只需要将子查询用括号括起即可如果在MySql中不写后面的关键字，则会有以下的错误信息Every derived table must have its own alias行号 rownum的书写规范在Oracle中查询行号，直接写rownum就可以，还能起别名在MySql中查寻行号，需要在rownum前加@，且不能起别名select @ROWNUM from TABLE
我要删除表中重复的最小id记录，发现这样删除 DELETE FROM test WHERE id =((SELECT MIN(id) MID FROM test GROUP BY NAME HAVING NAME='小明')) 会报 You can't specify target table 'test' for update in FROM clause 错误。翻译：对于更新中的from语句，
select * from student where sno in(select sno from sc group by sno having count(*)=(select count(*)from course))通过sc表中sno分组，如果总条数等于课程表总课程，说明已找出选修所有课程的学生no
Copyright © 2005-2025 51CTO.COM 版权所有 京ICP证060544号
