分组时TSQL选择最小和最大的行(TSQL Select Min & Max row when gr

2019-09-21 07:30发布

可以说,我有一个包含很多很多行像这样的表:

ID        Range         Range_begining        Profit
----------------------------------------------------
 1    (100-150)                    100           -20
 2    (200-250)                    200          40.2
 3    (100-150)                    100           100
 4    (450-500)                    450           -90
 ...

我做这样一个简单的查询:

SELECT max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
    FROM
        Orders
    GROUP BY
        Range_begining

该查询运行后,我得到这样的结果:

Range        Count        AVG Profit
------------------------------------
(100-150)        2                40
(200-250)        1              40.2
(450-500)        1               -90
 ...

非常简单 :)

我现在需要做的是用最小的和最大的利润,其中计数大于10大(这是一个参数)选择行

我能得到最小值与此:

SELECT TOP 1 [Range], [AVG Profit] FROM (
     SELECT max([Range]) AS 'Range'
         , count(ID) AS 'Count'
         , round(avg([Profit]), 2) AS 'AVG Profit'
        FROM
            Orders
        GROUP BY
            Range_begining) X
WHERE
    [Count]>10
ORDER BY 
    [AVG Profit] ASC --or DESC if I want max profit

我在想这样做的的UNION上面的查询与ORDER BY DESC,但它不是最好的解决办法。

我需要做什么:
通过分组范围时,一个最小的,第二个最大AVG利润:选择2行。

编辑:如果我加2移动列到我的主数据表是这样的:

ID        Range         Range_begining        Profit        OrderDate     Company
---------------------------------------------------------------------------------
 1    (100-150)                    100           -20        2012-01-02          1
 2    (200-250)                    200          40.2        2012-03-22          0
 3    (100-150)                    100           100        2012-02-05          0
 4    (450-500)                    450           -90        2012-05-12          1
 ...

然后尝试添加2个条件是这样的:

; with ordering as (
  SELECT max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
     , row_number() over (order by avg([Profit])) rn_min
     , row_number() over (order by avg([Profit]) desc) rn_max
    FROM
        Orders
    GROUP BY
        Range_begining
    HAVING COUNT(ID) > 10
    AND [Company]=@company
    AND (@from= '' OR [OrderDate]>=@from)
    AND (@to= '' OR [OrderDate]<=@to)
)
select [range], [count], [avg profit]
  from ordering
 where (rn_max = 1 or rn_min = 1)

我得到一个错误,因为[公司]和[订购日期]

因为它不是在聚合函数或GROUP BY子句是包含在HAVING子句中无效。

我怎样才能解决这个问题?

EDIT2得到它的工作!

; with ordering as (
  SELECT max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
     , row_number() over (order by avg([Profit])) rn_min
     , row_number() over (order by avg([Profit]) desc) rn_max
    FROM
        Orders
    WHERE
    [Company]=@company
    AND (@from= '' OR [OrderDate]>=@from)
    AND (@to= '' OR [OrderDate]<=@to)
    GROUP BY
        Range_begining
    HAVING COUNT(ID) > 10
)
select [range], [count], [avg profit]
  from ordering
 where (rn_max = 1 or rn_min = 1)

编辑3我可以回到另一列有这样的描述:

Range        AVG Profit               Description
-------------------------------------------------
(200-250)          40.2           Max profit here
(450-500)           -90     Min profit, well done

编辑4个快速答案(基于@NikolaMarkovinović答案):

; with ordering as (
  SELECT max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
     , row_number() over (order by avg([Profit])) rn_min
     , row_number() over (order by avg([Profit]) desc) rn_max
    FROM
        Orders
    WHERE
    [Company]=@company
    AND (@from= '' OR [OrderDate]>=@from)
    AND (@to= '' OR [OrderDate]<=@to)
    GROUP BY
        Range_begining
    HAVING COUNT(ID) > 10
)
    SELECT
    CASE WHEN rn_max=1 THEN 'This is max' ELSE 'Min' END AS 'Description'
    ,[range]
    ,[count]
    ,[avg profit]
    FROM ordering
    WHERE (rn_max = 1 or rn_min = 1)

Answer 1:

你可能会在使用一次做到这一点的窗函数 :

; with ordering as (
  SELECT max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
     , row_number() over (order by avg([Profit])) rn_min
     , row_number() over (order by avg([Profit]) desc) rn_max
    FROM
        Orders
    GROUP BY
        Range_begining
    HAVING COUNT(ID) > 10
)
select [range], [count], [avg profit],
       case when rn_max = 1 
            then 'Max profit'
            else 'Min profit'
        end Description
  from ordering
 where (rn_max = 1 or rn_min = 1)

在这里,在SQL小提琴例子 。



Answer 2:

这里是一个SQLFiddle例子 。 在你的最后一个问题查询,您可以使用具有代替嵌套查询:

select * from
(SELECT TOP 1
    max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
    FROM
        Orders
    GROUP BY
        Range_begining
    having count(id)>10
    order by round(avg([Profit]), 2) ASC
) a
union all
select * from 
(
SELECT TOP 1
    max([Range]) AS 'Range'
     , count(ID) AS 'Count'
     , round(avg([Profit]), 2) AS 'AVG Profit'
    FROM
        Orders
    GROUP BY
        Range_begining
    having count(id)>10
    order by round(avg([Profit]), 2) desc
)b


文章来源: TSQL Select Min & Max row when grouping