Transpose rows column in GetRows

问题

Below VBA code does the job, but I'm losing some 3 sec in the transpose part.

Is there a way I can get the same result or in the SQL query or in the getrows process without losing the 3 secs?

Sub LoadData()
Dim strCon, srtQry As String, tmpArray, tmpArray2, R As Variant, i, j As Long

Set cn = CreateObject("ADODB.Connection")
Set rs = CreateObject("ADODB.Recordset")

strCon = "DRIVER={MySQL ODBC 5.2 ANSI Driver};" & _
        "SERVER=localhost;" & _
        "DATABASE=tbname;" & _
        "USER=root;" & _
        "PASSWORD=pass;" & _
        "Port=3306;" & _
        "Option=3"

cn.Open strCon

srtQry = "SELECT * FROM `tbname` WHERE `FileDay` = 20131220"

Set rs = cn.Execute(srtQry)

tmpArray = rs.GetRows

cn.Close

tmpArray2 = TransposeArray(tmpArray)

End Sub

TransposeArray:

Public Function TransposeArray(InputArr As Variant) As Variant

Dim RowNdx, ColNdx, LB1, LB2, UB1, UB2 As Long, tmpArray As Variant

LB1 = LBound(InputArr, 1)
LB2 = LBound(InputArr, 2)
UB1 = UBound(InputArr, 1)
UB2 = UBound(InputArr, 2)

ReDim tmpArray(LB2 To LB2 + UB2 - LB2, LB1 To LB1 + UB1 - LB1)

For RowNdx = LB2 To UB2
    For ColNdx = LB1 To UB1
        tmpArray(RowNdx, ColNdx) = InputArr(ColNdx, RowNdx)
    Next ColNdx
Next RowNdx

TransposeArray = tmpArray

End Function

回答1:

There are a few optimisations you can apply

Declarations: you need to specify the data type of each variable
Remove redundant calculations in Redim
Use the more compact For loop structure
Specify your variants as arrays
And for most impact: Use a Sub rather than Function

These together will reduce run time of the Transpose by more than 50%

Public Sub TransposeArray(ByRef InputArr() As Variant, ByRef ReturnArray() As Variant)
    Dim RowNdx As Long, ColNdx As Long
    Dim LB1 As Long, LB2 As Long, UB1 As Long, UB2 As Long

    LB1 = LBound(InputArr, 1)
    LB2 = LBound(InputArr, 2)
    UB1 = UBound(InputArr, 1)
    UB2 = UBound(InputArr, 2)

    ReDim ReturnArray(LB2 To UB2, LB1 To UB1)

    For RowNdx = LB2 To UB2
    For ColNdx = LB1 To UB1
        ReturnArray(RowNdx, ColNdx) = InputArr(ColNdx, RowNdx)
    Next ColNdx, RowNdx

End Sub

Call it like this

TransposeArray tmpArray, tmpArray2

来源：https://stackoverflow.com/questions/20959824/transpose-rows-column-in-getrows

标签

mysql

performance

excel-vba

adodb

transpose