MariaDB 10.2

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Create table If Not Exists Employee (Id int, Name varchar(255), Salary int, DepartmentId int);
Create table If Not Exists Department (Id int, Name varchar(255));
insert into Employee (Id, Name, Salary, DepartmentId) values ('1', 'Joe', '70000', '1');
insert into Employee (Id, Name, Salary, DepartmentId) values ('2', 'Henry', '80000', '2');
insert into Employee (Id, Name, Salary, DepartmentId) values ('3', 'Sam', '60000', '2');
insert into Employee (Id, Name, Salary, DepartmentId) values ('4', 'Max', '90000', '1');
insert into Department (Id, Name) values ('1', 'IT');
insert into Department (Id, Name) values ('2', 'Sales');
SELECT * FROM 
     (
      SELECT d.Name as Department, e.Name as Employee, Salary,
      DENSE_RANK() OVER (PARTITION BY DepartmentId ORDER BY Salary DESC) rank
      FROM Employee e JOIN Department d ON e.DepartmentId = d.id
     ) t
    WHERE rank <= 3
    ORDER BY Department, rank;


Department
Employee
Salary
rank


IT
Max
90000
1

IT
Joe
70000
2

Sales
Henry
80000
1

Sales
Sam
60000
2