MySQL41--ORDER BY子句

ORDER BY子句

ORDER BY 子句用于根据指定的列对结果集进行排序；
ORDER BY 子句默认按照升序对记录进行排序；
如果ORDER BY子句发生在子查询内部，并且同时用于外部查询，那么外层优先；

升序关键字为ASC,降序为DESC

-- 查找所有图书，并且按salePrice降序排序 
SELECT id,bookname,salePrice FROM t13 
ORDER BY salePrice DESC;

-- 查询student表中,学员编号(sid),姓名(sname),性别(sex),分数(score),根据学员分数(score)降序排列
SELECT sid,sname,sex,score FROM student
ORDER BY score DESC;

-- 查询emp表中,员工编号(empno),员工姓名(ename),职位(job),入职时间(hiredate),根据员工姓名(ename)升序排列
SELECT empno,ename,job,hiredate FROM emp 
ORDER BY ename ASC;

-- 查询emp表中,员工编号(empno),员工姓名(ename),职位(job),入职时间(hiredate),根据入职时间(hiredate)降序排列
SELECT empno,ename,job,hiredate
FROM emp
ORDER BY hiredate DESC;

-- 查询emp表中,员工编号(empno),姓名(ename),工资(sal),部门编号(deptno),先根据部门编号(deptno)升序排列,再根据员工编号(empno)降序排列
SELECT empno,ename,sal,deptno
FROM emp
ORDER BY deptno ASC,empno DESC;

-- 查询student表中,学员编号(sid),姓名(sname),性别(sex),班级(sclASs),根据班级升序排列,再根据学员编号降序排列
SELECT sid,sname,sex,sclASs
FROM student
ORDER BY sclASs ASC,sid DESC;

-- 查询student表中,最后5条记录  ---面试题
SELECT * FROM student limit 10,5;
SELECT * FROM student ORDER BY sid DESC limit 5;