185. department top three salaries

SQL Schema

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 | 85000 | 1 |
| 2 | Henry | 80000 | 2 |
| 3 | Sam | 60000 | 2 |
| 4 | Max | 90000 | 1 |
| 5 | Janet | 69000 | 1 |
| 6 | Randy | 85000 | 1 |
| 7 | Will | 70000 | 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 (order of rows does not matter).

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+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT | Max | 90000 |
| IT | Randy | 85000 |
| IT | Joe | 85000 |
| IT | Will | 70000 |
| Sales | Henry | 80000 |
| Sales | Sam | 60000 |
+------------+----------+--------+
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# Write your MySQL query statement below
SELECT c.Name Department,
a.Name Employee,
a.salary Salary
FROM Employee a,
( SELECT (b.c,0) AS c,
a.Id
FROM Employee a
LEFT JOIN
( SELECT count(1) AS c,
a.Id
FROM Employee a,
(SELECT DepartmentId,
salary
FROM Employee b
GROUP BY DepartmentId,
salary) b
WHERE a.Salary < b.Salary
AND a.DepartmentId = b.DepartmentId
GROUP BY a.Id ) b ON a.Id = b.Id ) b,
Department c
WHERE a.DepartmentId = c.Id
AND a.Id = b.Id
AND b.c < 3