如何在SQL中根据月份动态地选择列

Question

需要你的帮助带来这样一种方式下面的格式..我很必须混淆每个月动态地带来格式，因为每个月的列名必须交换MO或Adj_M0

如果你看到我的例子

当你看到上面的格式，我需要每月。 例如：参考输出 - 1月（列名）将交换与输出比较 - Feb

类似它会交换每月的列，所以你可以请指导我如何带来我的输出格式。

希望你明白，请指导我或者给我一些示例代码

Answer 1

所以，让我们建立动态的SQL每次运行时间。开始，然后调整它以获得您想要的结果 -

Function fnMakeTheSQL(nMO As Long) As String 

    ' define the output SQL string, and initialize it to blanks 
    Dim sSQL As String 
    sSQL = "" 

    ' concat the first part of the SQL 
    sSQL = sSQL & " SELECT " 
    sSQL = sSQL & vbCrLf & " Name, " 
    sSQL = sSQL & vbCrLf & " M0, " 

    ' now the interesting part, the LOOPing to build Prior & This month-s columns 
    Dim iMO As Long 
    For iMO = 1 To nMO 
     sSQL = sSQL & vbCrLf & " M" & iMO & ", " 
    Next iMO 

    ' and more interesting part, the LOOPing to build Future ADJ columns 
    'Dim iMO As Long 
    For iMO = nMO + 1 To 12 
     sSQL = sSQL & vbCrLf & " ADJ_M" & iMO & ", " 
    Next iMO 

    ' strip off the trailing comma 
    sSQL = Left(sSQL, InStrRev(sSQL, ",") - 1) 

    ' concat the last part of the SQL 
    sSQL = sSQL & vbCrLf & " From yourTable " 
    sSQL = sSQL & vbCrLf & " Order By Name " 

    ' give it back to the caller 
    fnMakeTheSQL = sSQL 

End Function 

月份时为5，生成的SQL是 -

SELECT 
Name, 
M0, 
M1, 
M2, 
M3, 
M4, 
M5, 
ADJ_M6, 
ADJ_M7, 
ADJ_M8, 
ADJ_M9, 
ADJ_M10, 
ADJ_M11, 
ADJ_M12 
From yourTable 
Order By Name