有四个表
现在我需要编写一个查询，显示每个部门获得最高薪水的员工ID。
答案 0 :(得分：0)
您没有说明您正在使用哪种数据库（除非您打算 SQL = SQL-Server ）。所以这个解决方案不适合你。任何，它使用Oracle的分析函数RANK()来解决问题。
鉴于此数据......
SQL> select d.name
2 , e.name
3 , es.salary
4 from employee e join
5 emp_sal es on (es.employee_id = e.employee_id) join
6 emp_dep ed on (ed.employee_id = e.employee_id) join
7 department d on (d.department_id = ed.department_id)
8 order by d.department_id, es.salary desc
9 /
NAME NAME SALARY
---------- ---------- ----------
PRODUCTION GRINCH 1100
PRODUCTION CAT 1100
DELIVERY LORAX 3000
DELIVERY DAISY 2500
ACCOUNTS FOX 5000
ACCOUNTS KNOX 2500
ACCOUNTS SAM-I-AM 1200
7 rows selected.
SQL>
注意PRODUCTION中的关系，这就是为什么这会返回四行......
SQL> select dept_name
2 , emp_name
3 , salary
4 from (
5 select d.name as dept_name
6 , e.name as emp_name
7 , es.salary
8 , rank () over (partition by d.department_id
9 order by es.salary desc ) as rnk
10 from employee e join
11 emp_sal es on (es.employee_id = e.employee_id) join
12 emp_dep ed on (ed.employee_id = e.employee_id) join
13 department d on (d.department_id = ed.department_id)
14 )
15 where rnk = 1
16 order by salary desc
17 /
DEPT_NAME EMP_NAME SALARY
---------- ---------- ----------
ACCOUNTS FOX 5000
DELIVERY LORAX 3000
PRODUCTION GRINCH 1100
PRODUCTION CAT 1100
SQL>
修改
我使用员工姓名而不是ID，因为它使结果更容易阅读。您可以轻松替换所需的投影仪。
答案 1 :(得分：0)
这将为您提供最高工资的价值：
SELECT
department_id, MAX(es.salary) AS max_salary
FROM
emp_sal es JOIN emp_dep ed ON ed.employee_id = es.employee_id
GROUP BY ed.department_id
这将为您提供ID：
SELECT department_id, employee_id, max_values.max_salary
FROM
emp_sal es JOIN emp_dep ed ON ed.employee_id = es.employee_id
JOIN
(SELECT
department_id, MAX(es.salary) AS max_salary
FROM
emp_sal es JOIN emp_dep ed ON ed.employee_id = es.employee_id
GROUP BY ed.department_id) AS max_values
ON (ed.department_id = max_values.department_id AND es.salary = max_salary)
答案 2 :(得分：-1)
我认为以下内容应该有效 [EDITED]
SELECT
ed.department_id,
d.[name],
es.employee_id,
e.[name],
es.salary
FROM
emp_sal es
INNER JOIN emp_dep ed
ON ed.employee_id = es.employee_id
INNER JOIN employee e
ON e.employee_id = ed.employee_id
INNER JOIN department d
ON d.department_id = ed.department_id
WHERE
es.salary = (
SELECT
max(iEs.salary)
FROM
emp_sal iEs
INNER JOIN emp_dep iEd
ON iEd.employee_id = iEs.employee_id
WHERE
iEd.department_id = ed.department_id
)
为了显示员工和部门的名称，我做得有点复杂。
仅供员工ID使用
SELECT
es.employee_id
FROM
emp_sal es
INNER JOIN emp_dep ed
ON ed.employee_id = es.employee_id
WHERE
es.salary = (
SELECT
max(iEs.salary)
FROM
emp_sal iEs
INNER JOIN emp_dep iEd
ON iEd.employee_id = iEs.employee_id
WHERE
iEd.department_id = ed.department_id
)
答案 3 :(得分：-1)
创建我自己的测试表：
DECLARE @Employee TABLE (Employee_id INT, Name VARCHAR(MAX), Chief_id INT)
DECLARE @Department TABLE (Department_Id INT, Name VARCHAR(MAX))
DECLARE @Emp_Dep TABLE (Employee_id INT, Department_Id INT)
DECLARE @Emp_Sal TABLE (Employee_id INT, Salary DECIMAL)
INSERT INTO @Employee
SELECT 1, 'John Doe', 0 UNION ALL
SELECT 2, 'John Doe', 0 UNION ALL
SELECT 3, 'John Doe', 0 UNION ALL
SELECT 4, 'John Doe', 0 UNION ALL
SELECT 5, 'John Doe', 0 UNION ALL
SELECT 6, 'John Doe', 0 UNION ALL
SELECT 7, 'John Doe', 0;
INSERT INTO @Department
SELECT 1, 'Moomin' UNION ALL
SELECT 2, 'Moo' UNION ALL
SELECT 3, 'Min';
INSERT INTO @Emp_Dep
SELECT 1, 1 UNION ALL
SELECT 2, 1 UNION ALL
SELECT 3, 2 UNION ALL
SELECT 4, 2 UNION ALL
SELECT 5, 3 UNION ALL
SELECT 6, 3 UNION ALL
SELECT 7, 3;
INSERT INTO @Emp_Sal
SELECT 1, 1200 UNION ALL
SELECT 2, 1100 UNION ALL
SELECT 3, 2000 UNION ALL
SELECT 4, 2000 UNION ALL
SELECT 5, 3451 UNION ALL
SELECT 6, 3321 UNION ALL
SELECT 7, 3123;
如果他们被捆绑在一起，那么这个版本将是部门中的所有人：）
WITH [Merged] AS (
SELECT [@Employee].[Employee_id],
[@Employee].[Name],
[@Department].[Name] [Department],
[@Department].[Department_Id],
[@Emp_Sal].[Salary]
FROM @Employee
INNER JOIN @Emp_Sal ON [@Employee].[Employee_id] = [@Emp_Sal].[Employee_id]
INNER JOIN @Emp_Dep ON [@Emp_Sal].[Employee_id] = [@Emp_Dep].[Employee_id]
INNER JOIN @Department ON [@Emp_Dep].[Department_Id] = [@Department].[Department_Id]
)
SELECT [Main].Employee_id, [Main].Name, [Main].Department, [Main].Salary
FROM Merged [Main]
WHERE [Salary] = (SELECT MAX(Salary) FROM [Merged] WHERE Department_Id = [Main].Department_Id);
虽然这个版本只会从每个部门中选择1，但你必须找到一种方法让你想要的人在ROW_NUMBER（）OVER
之上。WITH [Merged] AS (
SELECT [@Employee].[Employee_id],
[@Employee].[Name],
[@Department].[Name] [Department],
[@Department].[Department_Id],
[@Emp_Sal].[Salary],
ROW_NUMBER() OVER(ORDER BY [@Department].[Department_Id] ASC, [@Emp_Sal].[Salary] DESC, [@Employee].[Employee_id] ASC) AS 'RowNumber'
FROM @Employee
INNER JOIN @Emp_Sal ON [@Employee].[Employee_id] = [@Emp_Sal].[Employee_id]
INNER JOIN @Emp_Dep ON [@Emp_Sal].[Employee_id] = [@Emp_Dep].[Employee_id]
INNER JOIN @Department ON [@Emp_Dep].[Department_Id] = [@Department].[Department_Id]
)
SELECT [Main].Employee_id, [Main].Name, [Main].Department, [Main].Salary
FROM Merged [Main]
WHERE [RowNumber] = (SELECT MAX(RowNumber) FROM [Merged] WHERE Department_Id = [Main].Department_Id);
值得一提的可能是它适用于Microsoft SQL Server！
答案 4 :(得分：-2)
select
e.employee_id
d.name as department,
max(s.salary) as msalary
from
department as d
right join emp_dep as e on e.department_id = d.department_id
left join emp_sal as s on s.employee_id = e.employee_id
group by d.name
或类似的东西