計算SQL中的最大值，最小值和平均值

Question

我正在運行下面的腳本。我在想，如果有人知道如何三個附加行添加到結果：

1.增加一個新行MAX值

2.加一個新行的最小值。

3.添加平均值的新行。

這是我的查詢，它運行在2006年4月和5月的兩個整月數據上。

SELECT 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'NUMBER'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 

該查詢將生成以下結果（部分），並在結果底部顯示所需的addtional行。

非常感謝， 喬

FY  DAY  STORE DATES  ITEM NOTE 
2006 Saturday ELEVEN 4/1/2006 14 NUMBER 
2006 Sunday  ELEVEN 4/2/2006 21 NUMBER 
2006 Monday  ELEVEN 4/3/2006 24 NUMBER 
-------------------------------------------------- 
-------------------------------------------------- 
-------------------------------------------------- 
2006 Monday  ELEVEN 5/29/2006 37 NUMBER 
2006 Tuesday  ELEVEN 5/30/2006 20 NUMBER 
2006 Wednesday ELEVEN 5/31/2006 25 NUMBER 
2006 Saturday ELEVEN 5/13/2006 5 MINIMUM 
2006 Tuesday  ELEVEN 5/16/2006 61 MAXIMUM 
2006    ELEVEN    25 AVERAGE 

Answer 1

建議你加載你的查詢到一個表變量第一。然後你可以執行你的元操作。然後將3行記錄到結果集上。

這種方法的好處：你是從同一個結果集計算

• 。如果您複製/粘貼3（最小，最大，平均）的查詢，您可能會讀取不同的數據，如果有另一個流程在計算時更新了行。如果/發生這種情況，與結果集中的原始數據相比，您的計算似乎不正確。

• 更少的代碼閱讀和維護

DECLARE @MyResults (TABLE) (FY int, DAY varchar(10), STORE varchar(10), DATES varchar(10), ITEM varchar(10), NOTE varchar(10)) 

DECLARE @MyCalcs TABLE (ForYear int, Item int, Note varchar(100)) 

--calc the avg, max and min 

INSERT INTO @MyCalcs (ForYear, Item, Note) 
    SELECT FY, AVG(ITEMS), 'Average' 
    FROM @MyResults GROUP BY FY 

INSERT INTO @MyCalcs (ForYear, Item, Note) 
    SELECT FY, Max(ITEMS), 'Max' 
    FROM @MyResults GROUP BY FY 

INSERT INTO @MyCalcs (ForYear, Item, Note) 
    SELECT FY, MIN(ITEMS), 'Min' 
    FROM @MyResults GROUP BY FY 

--union the discrete data with the calcs 
SELECT FY,DAY,STORE,DATES,ITEM,NOTE 
FROM @MyResults 
UNION ALL 
SELECT ForYear AS FY, '' AS Day, '' AS Store, Item, Note 
FROM @MyCalcs 

Answer 2

SELECT 0 as p, 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'NUMBER'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 

union 

SELECT 1 as p, 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
min(ITEMS)        AS ITEM, 
'MINIMUM'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 
having items = min(items) 
limit 1 

union 

SELECT 2 as p, 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
max(ITEMS)        AS ITEM, 
'MAXIMUM'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 
having items = max(items) 
limit 1 

union 

SELECT 3 as p, 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
''          AS DAY, 
STORE_NAME        AS STORE, 
''          DATES, 
avg(ITEMS)        AS ITEM, 
'AVERAGE'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 

order by p 

Answer 3

• 爲了使他們處於底部，你需要一個虛擬的排序列。
• 要添加額外的行，您需要將多個結果UNION-ed結合在一起。
• 要每組只有一行，您需要使用TOP，但每個UNION查詢只能使用一個TOP，因此您需要對它們進行子查詢。
• 日期如'04/1/2006'容易出現錯誤的DATEFORMAT設置。使用YYYYMMDD，例如20060104獲得可靠結果

在事務（隔離級別快照）中執行此操作以查看UNION部件之間的一致結果。

SELECT FY, DAY, STORE, DATES, ITEM, NOTE 
FROM 
(
SELECT Sorter=1, 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'NUMBER'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 
UNION ALL 
SELECT 2,* FROM (
SELECT TOP 1 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'MAX'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 
ORDER BY ITEM DESC) X 
UNION ALL 
SELECT 3,* FROM (
SELECT TOP 1 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'MIN'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE 
ORDER BY ITEM) X 
UNION ALL 
SELECT 4, FY, '', STORE, '', AVG(ITEM), NOTE 
FROM (
SELECT 
DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)) AS FY, 
DATENAME(WEEKDAY, SOLD_DATE)    AS DAY, 
STORE_NAME        AS STORE, 
CONVERT (VARCHAR, SOLD_DATE, 10)   DATES, 
SUM(ITEMS)        AS ITEM, 
'AVERAGE'         AS NOTE  
FROM MYTABLE 
WHERE SOLD_DATE >='04/1/2006' 
AND SOLD_DATE <'06/1/2006' 
AND STORE_NAME ='ELEVEN' 
GROUP BY DATEPART(YYYY, DATEADD(MM, 3, SOLD_DATE)), 
DATENAME(WEEKDAY, SOLD_DATE), STORE_NAME, SOLD_DATE) Y 
) X 
ORDER BY SORTER