185. Department Top Three Salaries

Description

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

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.

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).

Department	Employee	Salary
IT	Max	90000
IT	Randy	85000
IT	Joe	85000
IT	Will	70000
Sales	Henry	80000
Sales	Sam	60000

Constraints

Approach

Links

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Examples

Example 1

Input:

{"headers": {"Employee": ["Id", "Name", "Salary", "DepartmentId"], "Department": ["Id", "Name"]}, "rows": {"Employee": [[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]], "Department": [[1, "IT"], [2, "Sales"]]}}

Output:

{"headers": ["Department", "Employee", "Salary"], "values": [["IT", "Joe", 85000], ["Sales", "Henry", 80000], ["Sales", "Sam", 60000], ["IT", "Max", 90000], ["IT", "Randy", 85000], ["IT", "Will", 70000]]}

Explanation:

In IT department, Max earns the highest salary, both Randy and Joe earn the second highest salary, and Will earns the third highest salary. There are only two employees in the Sales department, Henry earns the highest salary while Sam earns the second highest salary.

Solutions

Solution 1

# MySQL query statement

SELECT dept.Name AS 'Department', emp.Name AS 'Employee', emp.Salary
FROM Employee emp
JOIN Department dept 
ON emp.DepartmentId = dept.Id
WHERE 3 > (SELECT COUNT(DISTINCT emp2.Salary)
            FROM Employee emp2
            WHERE emp2.Salary > emp.Salary 
                        AND emp.DepartmentId = emp2.DepartmentId);

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