LeetCode | database | Department Top Three Salaries

• 题目描述：
  已知某公司员工的employee表和department表，写一个sql查询语言找出每个部门工资排前三的员工信息。
  employee:
  
  department:
  
  输出结果：
  

• 题目解答
  where条件语句的意思是：在该部门中比这三名员工中任一位工资高的人不超过3人。

SELECT d.Name AS 'Department', e1.Name AS 'Employee', e1.Salary
FROM
    Employee e1
        JOIN
    Department d ON e1.DepartmentId = d.Id
WHERE
    (SELECT
            COUNT(DISTINCT e2.Salary)
        FROM
            Employee e2
        WHERE
            e2.Salary > e1.Salary
                AND e1.DepartmentId = e2.DepartmentId
        )<3