在VBA-Excel中将1个Sub分为2个Sub时出现“下标超出范围”错误

Question

I wrote a VBA-SQL code in a "Module" which reads a table from a sheet, then it sends the table to server via SQL-code. I am saving each column as an array result1(), result2(), result3() , and Col1, Col2 are just column names in the server. it is index for the arrays (same index for all arrays) The VBA-SQL code is something like this. And this Sub works perfectly:

Sub Datasend_Click()

Dim result1() As Variant, result2() As Variant, result3() As Variant
Dim Col1 As String, Col2 As String, Col3 As String
Dim it As Integer

    Set ValidSheet = Worksheets("Sheet2")
    Set DataRange = ValidSheet.Range("C22:C81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result1(it)
            result1(it) = dataa.Value
            it = it + 1
    Next


     Set DataRange = ValidSheet.Range("D22:D81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result2(it)
            result2(it) = dataa.Value
            it = it + 1
    Next

 For it = 1 To 60

    SQL = "INSERT INTO PaymentPattern (" & Col1 & ", " & Col2 & ", " & Col3 & ") "
    SQL = SQL & "VALUES (" & Str(result1(it)) & ", " & Str(result2(it)) & ", " & Str(result3(it)) & ")"

    dbclass.ExecuteSQL SQL

  Next it

End Sub

However, I want to separate this Sub into 2 Sub's instead. The first Sub will read and save the arrays from the sheet (then I can use the arrays for other Sub's ), and the second Sub will call the first Sub and run the SQL-code to send the arrays to the server. I wrote 2 Sub's like below, but I get an error like "Subscript out of range" for the line SQL = SQL & "VALUES (" & Str(result1(it)) & ", " & Str(result2(it)) & ", " & Str(result3(it)) & ")" . When I debug it, it shows that it=1 as normal, but it shows "Subcript out of range" for the result1(it) . Can you say please what is wrong?

Sub arrayread()
  Dim result1() As Variant, result2() As Variant, result3() As Variant
  Dim it As Integer

    Set ValidSheet = Worksheets("Sheet2")
    Set DataRange = ValidSheet.Range("C22:C81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result1(it)
            result1(it) = dataa.Value
            it = it + 1
    Next


     Set DataRange = ValidSheet.Range("D22:D81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result2(it)
            result2(it) = dataa.Value
            it = it + 1
    Next


End Sub

---

Sub Datasend_Click()
  Dim result1() As Variant, result2() As Variant, result3() As Variant
  Dim it As Integer
  Dim Col1 As String, Col2 As String, Col3 As String

  arrayread

  For it = 1 To 60

    SQL = "INSERT INTO PaymentPattern (" & Col1 & ", " & Col2 & ", " & Col3 & ") "
    SQL = SQL & "VALUES (" & Str(result1(it)) & ", " & Str(result2(it)) & ", " & Str(result3(it)) & ")"

    dbclass.ExecuteSQL SQL

  Next it

End Sub

Answer 1

It comes down to the scope of the arrays (where they are declared). You are declaring them separately in each sub, so result1 in Datasend_Click knows nothing about result1 from arrayread . Therefore, result1 and result2 will be empty in the second sub which causes your Subscript out of range error, given you have no elements yet you are trying to access it.

Here is a Microsoft article outlining VBA variable scope: https://support.microsoft.com/en-us/kb/141693 . Chip Pearson also has a good article on this subject: http://www.cpearson.com/excel/scope.aspx

You should move the declaration of result1 and result2 to the top of your Module (above the Sub s) so they they have Class Level scope (available to all methods in the Module).

Dim result1() As Variant, result2() As Variant, result3() As Variant


Sub arrayread()
  Dim it As Integer

    Set ValidSheet = Worksheets("Sheet2")
    Set DataRange = ValidSheet.Range("C22:C81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result1(it)
            result1(it) = dataa.Value
            it = it + 1
    Next


     Set DataRange = ValidSheet.Range("D22:D81")
        it = 1
    For Each dataa In DataRange
        ReDim Preserve result2(it)
            result2(it) = dataa.Value
            it = it + 1
    Next


End Sub

Sub Datasend_Click()

  Dim it As Integer
  Dim Col1 As String, Col2 As String, Col3 As String

  arrayread

  For it = 1 To 60

    SQL = "INSERT INTO PaymentPattern (" & Col1 & ", " & Col2 & ", " & Col3 & ") "
    SQL = SQL & "VALUES (" & Str(result1(it)) & ", " & Str(result2(it)) & ", " & Str(result3(it)) & ")"

    dbclass.ExecuteSQL SQL

  Next it

End Sub 

My preferred solution would be to be passing the results in and out of the methods rather than having module-level scope, as this can cause spaghetti code issues down the track.