leetcode-185-Department-Top-Three-Salaries

描述


The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id.

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+----+-------+--------+--------------+
| Id | Name | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1 | Joe | 70000 | 1 |
| 2 | Henry | 80000 | 2 |
| 3 | Sam | 60000 | 2 |
| 4 | Max | 90000 | 1 |
| 5 | Janet | 69000 | 1 |
| 6 | Randy | 85000 | 1 |
+----+-------+--------+--------------+

The Department table holds all departments of the company.

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+----+----------+
| Id | Name |
+----+----------+
| 1 | IT |
| 2 | Sales |
+----+----------+

Write a SQL query to find employees who earn the top three salaries in each of the department. For the above tables, your SQL query should return the following rows.

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+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT | Max | 90000 |
| IT | Randy | 85000 |
| IT | Joe | 70000 |
| Sales | Henry | 80000 |
| Sales | Sam | 60000 |
+------------+----------+--------+

分析


找出每个部门里工资最高的三个员工

解决方案(MySQL)


类似于上一道题,不用分组或排序,只需要将筛选的条件修改一下:

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# Write your MySQL query statement below

SELECT d.Name AS Department, e.Name AS Employee, e.Salary AS Salary
FROM Employee AS e, Department AS d
WHERE e.DepartmentId=d.Id AND 3 > (
SELECT COUNT(DISTINCT tmp.Salary)
FROM Employee AS tmp
WHERE tmp.Salary > e.Salary AND
tmp.DepartmentId=e.DepartmentId
)

题目来源