检索信息的SQL查询

Question

SELECT * 
FROM EMPLOYEE a 
     LEFT JOIN EMPLOYEE b 
      ON a.Employee_ID <> b.Employee_ID 
WHERE a.employee_salary < b.employee_salary and a.Department_ID='30' 

你好，我想检索赚更多的钱比部门的员工的员工的所有信息30

image of database

Answer 1

SELECT * FROM EMPLOYEE 
where (Department_ID<>'30') 
and 
(
employee_salary > 
    (select max(employee_salary) from EMPLOYEE where Department_ID='30') 
) 

或者使用MAX的SUM istead如果你需要员工的是赚取更多的所有部门30

Answer 2

分割问题将帮助我们：

• 第一个：您需要知道有多少钱可以赚取30名员工。
• 第二：以赚取莫拉比这笔钱的员工。

简单的方法是使用子查询进行查询。主查询检索员工的收入超过X，子查询返回X。

子查询 多少钱可以赚30个员工？

Select employee_salary from employee where Department_ID='30' 

主查询与子查询： 员工说赚得莫拉比这个钱：

Select * from employee 
where employee_salary > ANY (
    Select employee_salary from employee where Department_ID='30' 
) 

通知比你可以在子查询操作使用ANY或ALL：

• ALL手段你正在寻找员工的收入超过ALL dpt 30名员工。
• ANY意味着您正在寻找的员工数量超过了dpt 30名员工的ANY。

Answer 3

SELECT * fROM EMPLOYEE a where a.Department_ID!='30' 
and (a.employee_salary > (select max(b.employee_salary) 
from EMPLOYEE b where b.Department_ID='30'))