MySQL排序和分页（三）

使用order by排序
asc(ascend):升序
desc(descend)降序
order by 句子在select 语句结尾
练习

1. 查询员工的姓名和部门号和年薪，按年薪降序 按姓名升序显示
   SELECT last_name,department_id,salary * 12 annual_sal
   FROM employees
   ORDER BY annual_sal 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，显示第
   21到40位置的数据
   SELECT last_name,salary
   FROM employees
   WHERE salary NOT BETWEEN 8000 AND 17000
   ORDER BY salary DESC
   LIMIT 20,20;

3. 查询邮箱中包含 e 的员工信息，并先按邮箱的字节数降序，再按部门号
   升序
   SELECT last_name,email,department_id
   FROM employees
   #where email like ‘%e%’
   WHERE email REGEXP ‘[e]’
   ORDER BY LENGTH(email) DESC,department_id ASC;