[SQL]LeetCode184. 部门工资最高的员工 | Department Highest Salary

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

+----+-------+--------+--------------+
| Id | Name  | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1  | Joe   | 70000  | 1            |
| 2  | Henry | 80000  | 2            |
| 3  | Sam   | 60000  | 2            |
| 4  | Max   | 90000  | 1            |
+----+-------+--------+--------------+

The Department table holds all departments of the company.

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

Write a SQL query to find employees who have the highest salary in each of the departments. For the above tables, Max has the highest salary in the IT department and Henry has the highest salary in the Sales department.

+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT         | Max      | 90000  |
| Sales      | Henry    | 80000  |
+------------+----------+--------+

---

Employee 表包含所有员工信息，每个员工有其对应的 Id, salary 和 department Id。

+----+-------+--------+--------------+
| Id | Name  | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1  | Joe   | 70000  | 1            |
| 2  | Henry | 80000  | 2            |
| 3  | Sam   | 60000  | 2            |
| 4  | Max   | 90000  | 1            |
+----+-------+--------+--------------+

Department 表包含公司所有部门的信息。

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

编写一个 SQL 查询，找出每个部门工资最高的员工。例如，根据上述给定的表格，Max 在 IT 部门有最高工资，Henry 在 Sales 部门有最高工资。

+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT         | Max      | 90000  |
| Sales      | Henry    | 80000  |
+------------+----------+--------+

---

236ms

# Write your MySQL query statement below
select 
D.Name as Department,
E.name as Employee,
Salary
from Employee E 
join Department D 
on E.DepartmentId=D.Id 
where (E.DepartmentId,E.Salary) IN 
(select DepartmentId,max(Salary) 
 from Employee 
 group by DepartmentId)

---

239ms

select department.name as 'Department',employee.name as 'Employee',salary as 'Salary' from employee join department on employee.departmentid = department.id where (employee.departmentid,employee.salary) in (select departmentid, max(salary) from employee group by departmentid)

---

244ms

# Write your MySQL query statement below

SELECT
    Department.name AS 'Department',
    Employee.name AS 'Employee',
    Salary
FROM
    Employee
        JOIN
    Department ON Employee.DepartmentId = Department.Id
WHERE
    (Employee.DepartmentId , Salary) IN
    (   SELECT
            DepartmentId, MAX(Salary)
        FROM
            Employee
        GROUP BY DepartmentId
    )
;

---

252ms

# Write your MySQL query statement below

SELECT t2.name as Department, t1.Name as employee, t1.salary
FROM employee t1
JOIN department t2
ON t1.departmentid = t2.id
WHERE (t1.departmentid, t1.salary) in 
        (SELECT departmentid, MAX(salary)
        FROM employee
        GROUP BY 1)
ORDER BY 1, 3 DESC