mysql-3-orderby

#进阶3：排序查询
/*
语法：
SELECT 
FROM
WHERE
ORDER BY ASC|DESC
*/

USE myemployees;

#案例1：查询员工信息，按工资从高到低排
SELECT *
FROM employees
ORDER BY salary;


#案例2：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;


#案例3：按年薪高低显示员工信息和年薪
SELECT *, salary*12*(1+IFNULL(commission_pct, 0)) AS 年薪
FROM employees
ORDER BY 年薪 DESC;


#案例4：按姓名长度排序
SELECT *, salary*12*(1+IFNULL(commission_pct, 0)) AS 年薪
FROM employees
ORDER BY Length(last_name);


#案例5：查询员工信息，先按工资、再按员工编号
SELECT *
FROM employees
ORDER BY salary, employee_id DESC;

SELECT *
FROM employees
ORDER BY salary DESC, employee_id;


#案例6：工资不带8000到17000之间的员工的姓名和工资，按工资降序
SELECT Concat(last_name, ‘ ‘, first_name) AS "name", salary
FROM employees
WHERE salary NOT BETWEEN 8000 AND 17000
ORDER BY salary DESC;