摘要: 一、子查询:eg1: SELECT enameFROM emp WHERE sal > (SELECT sal FROM emp WHERE empno=7566);eg2: SELECT a.ename, a.sal, a.deptno, b.salavg FROM em... 阅读全文
posted @ 2015-04-29 13:31 qian@@jing 阅读(153) 评论(0) 推荐(0)