多个子选择查询中的问题

Question

我需要找到与PETER具有相同功能或工资大于或等于SANDERS的所有员工的name、function、officename和salary。按function 和salary 订购。

有两个表：office 和 employee

表 office 包含：

officenumber

name

city

表employee 包含：

employeenumber
name
function
manager
sal
officenumber

这是我当前的 SQL 查询：

SELECT  NAME,
        FUNCTION,
        SAL
FROM    EMPLOYEE
WHERE   FUNCTIE   =   (SELECT     FUNCTION
                       FROM       EMPLOYEE
                       WHERE      NAME = 'PIETERS')

我被这个查询卡住了。

Answer 1

假设这是 SQL Server（您从未指定），这样的事情应该可以工作。

SELECT
    e.name,
    e.function,
    e.sal,
    o.name AS officename
FROM employee e 
    JOIN office o ON e.officenumber = o.officenumber
WHERE
    e.function = (SELECT function FROM employee WHERE name = 'PIETERS') OR
    e.sal >= (SELECT sal FROM employee WHERE name = 'SANDERS')
ORDER BY e.function, e.salary

如果您使用的是 MySQL 或其他东西，则必须稍微调整一下。

Answer 2

你需要在这里做三件事：
1. 连接两个表，因为您需要两个表的结果
2. 根据两个条件过滤结果
3.排序结果：

第一部分很简单，只需要根据officenumber加入即可：

select e.name, e.function, o.name as officeName, e.salary from
  employee e inner join office o 
  on e.officenumber = o.officenumber

第二部分，简单的where子句：

  where e.function = (select function from employee where name = 'PETER') 
  or e.salary >= (select salary from employee where name = 'SANDERS')

最后，排序：

  order by e.function, e.salary

把它们放在一起：

select e.name, e.function, o.name as officeName, e.salary from
  employee e inner join office o 
  on e.officenumber = o.officenumber
  where e.function = (select function from employee where name = 'PETER') 
  or e.salary >= (select salary from employee where name = 'SANDERS')
  order by e.function, e.salary