Mysql排序查询

Posted 2021-03-04 enoch-m

#排序查询
/*
语法:select 查询列表 from 表 [where 筛选条件] order by 排序序列 [asc/desc]

*/
SELECT * FROM employees ORDER BY salary DESC; #默认是asc(升序)

#查询部门编号>=90的员工信息，按入职时间的先后排序
SELECT * FROM employees WHERE department_id>=90 ORDER BY hiredate ASC;

#按年薪的高低显示员工的信息和年薪
SELECT *,salary*12*(1+IFNULL(commission_pct,0)) 年薪 FROM employees ORDER BY 年薪 DESC;

#按姓名的长度显示员工的姓名和工资（按函数排序）
SELECT LENGTH(last_name) 字节长度,last_name,salary FROM employees ORDER BY LENGTH(last_name) DESC;

#查询员工信息，要求先按工资升序排序，再按员工编号降序排
SELECT * FROM employees ORDER BY salary ASC, employee_id DESC;

#查询邮箱有e的员工信息，按邮箱字节长度降序排序，然后按部门编号排序
SELECT * FROM employees WHERE email LIKE ‘%e%‘ ORDER BY LENGTH(email) DESC, department_id ASC;