练习

#1.查询员工的姓名和部门和年薪，按年薪降序，按姓名升序
SELECT
    last_name,department_id,12*salary*(1+IFNULL(commission_pct,0)) AS 年薪
FROM
    employees
ORDER BY
    年薪 DESC,last_name ASC;
#2.选择工资不在8000到17000的员工的姓名和工资，按工资降序
SELECT
    last_name,salary
FROM
    employees
WHERE
    #salary not between 8000 and 17000
    salary < 8000 OR salary > 17000
ORDER BY
    salary DESC;
#3.查询邮箱中包含 e 的员工信息，并按邮箱的字节数降序，再按部门编号升序
SELECT
    *
FROM
    employees
WHERE
    email LIKE '%e%'
ORDER BY  
    LENGTH(email) DESC,department_id ASC;