我可以在SQL中創建一個select語句嗎？

Question

SELECT Count(*) AS MonthTotal 
FROM CRMProjects 
WHERE CreatedDate between '01 May 2016' and '31 May 2016' 

SELECT Count(*) AS YearTotal 
FROM CRMProjects 
WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016' 

SELECT Count(*) AS MonthNew 
FROM CRMProjects 
WHERE CreatedDate between '01 May 2016' and '31 May 2016' 
AND SystemType = 'O' 

SELECT Count(*) AS YearClosed 
FROM CRMProjects 
WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016' 
AND SystemType = 'C' 

它只填充表中的月份，它不填充其他部分，因爲Visual Studio不允許多個select語句用於一個數據集。

Answer 1

我建議是這樣的：

SELECT 'Month Total' AS Label, Count(*) AS Value 
FROM CRMProjects 
WHERE CreatedDate between '01 May 2016' and '31 May 2016' 

UNION ALL 

SELECT 'Year Total' AS Label, Count(*) AS Value 
FROM CRMProjects 
WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016' 

UNION ALL 

SELECT 'Month New' AS Label, Count(*) AS Value 
FROM CRMProjects 
WHERE CreatedDate between '01 May 2016' and '31 May 2016' 
AND SystemType = 'O' 

UNION ALL 

SELECT 'Year Closed' AS Label, Count(*) AS Value 
FROM CRMProjects 
WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016' 
AND SystemType = 'C' 

Answer 2

您可以使用SUM(CASE)作爲一種SUMIF這...

SELECT 
    SUM(CASE WHEN CreatedDate between '01 May 2016' and '31 May 2016' THEN 1 END) AS MonthTotal, 
    SUM(1) AS YearTotal, 
    SUM(CASE WHEN CreatedDate between '01 May 2016' and '31 May 2016' AND SystemType = 'O' THEN 1 END) AS MonthNew, 
    SUM(CASE WHEN SystemType = 'C' THEN 1 END) AS YearClosed 
FROM 
    CRMProjects 
WHERE 
    CreatedDate between '01 Jan 2016' and '31 Dec 2016' 

這樣可以確保只有掃描的相關部分表一次，一次彙總結果。

Answer 3

選擇每個數作爲自己的一列：

Select 
    (SELECT Count(*) 
     FROM CRMProjects 
     WHERE CreatedDate between '01 May 2016' and '31 May 2016') AS MonthTotal, 


    (SELECT Count(*) 
     FROM CRMProjects 
     WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016') AS YearTotal, 


    (SELECT Count(*) 
     FROM CRMProjects 
     WHERE CreatedDate between '01 May 2016' and '31 May 2016' 
     AND SystemType = 'O') AS MonthNew, 


    (SELECT Count(*) 
     FROM CRMProjects 
     WHERE CreatedDate between '01 Jan 2016' and '31 Dec 2016' 
     AND SystemType = 'C') AS YearClosed