select rownum r,s.* from (select ename,sal from emp order by sal ) s;这个就对
select rownum r,* from (select ename,sal from emp order by sal ) s;这个报异常,缺失表达式
select rownum r,s.* from (select ename,sal from emp order by sal ) s;这个就对
select rownum r,* from (select ename,sal from emp order by sal ) s;这个报异常,缺失表达式
s.* 表示表s的全部字段;
只写*,数据库无法判断*所代表的内容;
对于该sql语句可以做写优化。
建议看下 MySQL如何优化ORDER BY http://www.data.5helpyou.com/article246.html