12_MySQL如何对查询结果进行排序

本节所涉及的sql语句：

-- 排序关键字

SELECT empno,ename,hiredate FROM t_emp ORDER BY hiredate DESC;

-- 排序字段相同的情况

SELECT empno,ename,sal,hiredate FROM t_emp ORDER BY sal ASC,hiredate DESC;

SELECT empno,ename,sal,hiredate FROM t_emp ORDER BY sal ASC LIMIT 5;

此时字段sal是无序的

此时sal就变得有序了