SQL：查找所有引用的行都满足特定条件的行答案

【问题标题】：SQL: find all rows which have referenced rows that all meet certain conditionsSQL：查找所有引用的行都满足特定条件的行
【发布时间】：2015-03-19 22:52:55
【问题描述】：

两张桌子。一对多。如何找到所有员工都在 IT 部门工作且年薪超过 150000 美元的所有公司？

[COMPANIES]

|----|--------------| 
| id | company_name |
|----|--------------|
| 1  | Google       |
| 2  | Apple        |
|----|--------------| 

[EMPLOYEES]

|----|------------|------|------------|--------|
| id | company_id | name | department | salary |
|----|------------|------|------------|--------|
| 1  | 1          | John | IT         | 200000 |
| 2  | 1          | Bob  | IT         | 200000 |
| 3  | 2          | Rick | Design     | 100000 |
| 4  | 2          | Bill | Design     | 100000 |
|----|------------|------|------------|--------|

【问题讨论】：

标签： sql sqlite

【解决方案1】：

你可以使用EXISTS + NOT EXISTS:

SELECT c.*
FROM COMPANIES c
WHERE EXISTS
(
    SELECT 1 FROM EMPLOYEES e
    WHERE e.company_id = c.id
     AND  e.salary > 150000 
     AND  e.department = 'IT'
)
AND NOT EXISTS
(
   SELECT 1 FROM EMPLOYEES e
   WHERE e.company_id = c.id
     AND  (e.salary <= 150000 OR  e.department <> 'IT')
)

Demo

【讨论】：

【解决方案2】：

我认为你可以使用having 子句得到你想要的：

select company_id
from employees
group by company_id
having min(department) = max(department) and
       min(department) = 'IT' and
       min(salary) >= 150000;

如果你想要公司名称，你可以加入：

select c.id, c.company_name
from companies c join
     employees e
     on c.id = e.company_id
group by c.id, c.company_name
having min(department) = max(department) and
       min(department) = 'IT' and
       min(salary) >= 150000;

【讨论】：

@CL。 . . .谢谢。