Question

我试图在单个查询中查找列的Max，min，avg和last值。平台：SQL Server 2012

样本表：

SN  Month  Acc  Bal
------------------------
1     7    101   1,000/-
2     7    101   1,500/-
3     7    101   1,700/-
4     8    101   1,200/-
5     8    101   900/-
6     9    101   2,500/-

查询我写道：

select 
    [Month], [Acc],
    min(Bal) as MinBal,
    avg(Bal) as AvgBal,
    max(Bal) as MaxBal
    --, ??? for as LastBal
from 
    MyTable
Group By 
    [Month], [Acc]

使用Last_Value查询将返回所有记录而不是聚合记录

select 
    [Month], [Acc],
    min(Bal) as MinBal,
    avg(Bal) as AvgBal,
    max(Bal) as MaxBal,
    LAST_VALUE(Bal) OVER (partition by [Acc] order by [Month]) as LastBal
from 
    MyTable
Group By 
    [Month], [Acc], Bal

同样包括last_value(bal)正在按列表

生成错误

列'Bal'在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中。

Answer 1

请尝试此解决方案 -

数据生成

CREATE TABLE Alls
(
     SN INT
    ,[Month] INT
    ,Acc INT
    ,Bal INT
)
GO

INSERT INTO Alls VALUES
(1,  7,    101,   1000),
(2,  7,    101,   1500),
(3,  7,    101,   1700),
(4,  8,    101,   1200),
(5,  8,    101,   900),
(6,  9,    101,   2500)
GO

<强>解

SELECT sn,Acc,[Month] ,Bal
, MIN(Bal) OVER(PARTITION BY Acc,[Month]) MinBal
, AVG(Bal*1.) OVER(PARTITION BY Acc,[Month]) AvgBal
, MAX(Bal) OVER(PARTITION BY Acc,[Month]) MaxBal
, FIRST_VALUE(Bal) OVER(PARTITION BY Acc,[Month] ORDER BY SN DESC) lastVal
FROM Alls
ORDER By SN

<强>输出

sn          Acc         Month       Bal         MinBal      AvgBal           MaxBal      lastVal
----------- ----------- ----------- ----------- ----------- ---------------- ----------- -----------
1           101         7           1000        1000        1400.000000      1700        1700
2           101         7           1500        1000        1400.000000      1700        1700
3           101         7           1700        1000        1400.000000      1700        1700
4           101         8           1200        900         1050.000000      1200        900
5           101         8           900         900         1050.000000      1200        900
6           101         9           2500        2500        2500.000000      2500        2500

(6 rows affected)

如果您只需要acc，month和其他汇总列，请使用以下 -

<强>解

SELECT Acc,[Month],MAX(MinBal)MinBal,MAX(AvgBal)AvgBal,MAX(MaxBal)MaxBal,MAX(lastVal)lastVal
FROM
(
    SELECT sn,Acc,[Month] ,Bal
    , MIN(Bal) OVER(PARTITION BY Acc,[Month]) MinBal
    , AVG(Bal*1.) OVER(PARTITION BY Acc,[Month]) AvgBal
    , MAX(Bal) OVER(PARTITION BY Acc,[Month]) MaxBal
    , FIRST_VALUE(Bal) OVER(PARTITION BY Acc,[Month] ORDER BY SN DESC) lastVal
    FROM Alls
)u GROUP BY Acc,[Month]

<强>输出

Acc         Month       MinBal      AvgBal           MaxBal      lastVal
----------- ----------- ----------- ---------------- ----------- -----------
101         7           1000        1400.000000      1700        1700
101         8           900         1050.000000      1200        900
101         9           2500        2500.000000      2500        2500

(3 rows affected)

Answer 2

select * 
from 
( SELECT sn, Acc, [Month], Bal
       , MIN(Bal) OVER(PARTITION BY Acc, [Month]) MinBal
       , AVG(Bal) OVER(PARTITION BY Acc, [Month]) AvgBal
       , MAX(Bal) OVER(PARTITION BY Acc, [Month]) MaxBal
       , row_number() OVER(PARTITION BY Acc, [Month] ORDER BY SN DESC) as rn 
) tt
where rn = 1
ORDER By sn

Answer 3

您可以达到以下目标：

select 
 tt.Month
, tt.Acc
, min(Bal) as MinBal
, avg(Bal) as AvgBal 
, max(Bal) as MaxBal
, latest.balance
FROM #tbl1 as tt 
JOIN (
  SELECT 
  id
  ,month
  ,acc
  ,bal as balance
FROM #tbl1 AS t1
WHERE id = (SELECT MAX(id)
                 FROM #tbl1 AS t2 
                 WHERE t1.month = t2.month 
                   AND t1.acc = t2.acc 
                 GROUP BY month, acc)
) as latest
on tt.month = latest.month 
                   AND tt.acc = latest.acc 
Group By tt.Month, tt.Acc, latest.balance


DROP TABLE #tbl1

查询TSQL中的Min，Max，Avg和Last Value

3 个答案: