使用MySQL GROUP BY查找第三大价值

zdwk9cvp  于 2023-03-07  发布在  Mysql
关注(0)|答案(5)|浏览(134)

我有一个3列的表:
一个月一个月一个月一个月一个月一个月一个月一个月一个月二个月一个月
如何确定使用一个查询在每个department中查找第三高的salary

yiytaume

yiytaume1#

一种方法是LIMIT一个相关子查询,但它不是特别有效:

SELECT   department, (
  SELECT   salary
  FROM     my_table t2
  WHERE    t2.department = t1.department
  ORDER BY salary DESC
  LIMIT    2, 1
)
FROM     my_table t1
GROUP BY department
72qzrwbm

72qzrwbm2#

除了埃格亚尔的精彩回答之外,下面这个查询还能给予薪酬与第三名相当的员工的姓名(在每个部门):

SELECT 
    t.name, t.department, t.salary AS third_salary
FROM
    ( SELECT DISTINCT department 
      FROM tableX
    ) AS d
  JOIN
    tableX AS t
      ON  t.department = d.department 
      AND t.salary = 
      ( SELECT tt.salary                         -- notice that this
        FROM tableX AS tt                        -- subquery is
        WHERE tt.department = d.department       -- exactly the same as
        ORDER BY tt.salary DESC                  -- the one in 
          LIMIT 1 OFFSET 2                       -- @eggyal's answer
      ) ;
91zkwejq

91zkwejq3#

此RANK问题与以下问题类似:MySQL, Get users rank
我可以告诉你:

SELECT  s.*,
        (
        SELECT  COUNT(*)
        FROM    salaries si
        WHERE   si.salary >= s.salary AND si.department = s.department
        ) AS rank
FROM    salaries s
WHERE s.rank = 3
u5rb5r59

u5rb5r594#

试试这个:

SELECT name, department, salary
FROM (SELECT name, department, salary, IF(@dept=(@dept:=department), @auto:=@auto+1, @auto:=1) indx 
      FROM employee e, (SELECT @dept:=0, @auto:=1) A
      ORDER BY department, salary DESC ) AS A 
WHERE indx = 3;
jexiocij

jexiocij5#

试试这个简单而优雅的解决方案:

-- get second and third highest employee based on salary from all departments
WITH rankedemployee AS (
    SELECT
        *,
        DENSE_RANK() OVER (PARTITION BY departmentid ORDER BY salary DESC) AS denserank
    FROM employee
)
SELECT * FROM rankedemployee WHERE denserank IN (2,3);

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