Combining two tables in Excel using VBA

Question

Using Excel VBA I would like to be able to combine two tables in excel with a common key. I have suggested ADODB as a method,but am open to any other more efficient/elegant

Answer 1

Depending on whether or not you have duplicate values on either sheet, I could think of a few ideas, not using SQL though.

• Get LastRow of SourceSheet1 & SourceSheet2 - Set them as variables lastRow1 & lastRow2
• Create a row ticker for each sheet. s1Row, s2Row, tRow
• set tRow = 2 For the TargetSheet's first line
• Use For loop to cycle through each row of SourceSheet1. Using something like this
• When the first part of code is done looping, you will be finished adding every item from SourceSheet1 onto the TargetSheet. Then you will have to check the values from SourceSheet2 to see if any were unique to that list.
• When that is done, you should have only added the ones that were missing from your initial search. Then the targetSheet will be in the order of SourceSheet1 All Items, then the extra items from SourceSheet2

SET VARIABLES

Private Sub JoinLists()

Dim rng As Range
Dim typeName As String
Dim matchCount As Integer
Dim s1Row As Integer
Dim s2Row As Integer
Dim tRow As Integer
Dim m As Integer
Dim lastRow1 As Integer
Dim lastRow2 As Integer
Dim SourceSheet1 As String
Dim SourceSheet2 As String
Dim TargetSheet As String

SourceSheet1 = "Source1"
SourceSheet2 = "Source2"
TargetSheet = "Target"

tRow = 2

lastRow1 = Sheets(SourceSheet1).Range("A65536").End(xlUp).row
lastRow2 = Sheets(SourceSheet2).Range("A65536").End(xlUp).row

PHASE ONE: Copying every entry from Sheet1 to Target, while grabbing matches from Sheet2

Set rng = Sheets(SourceSheet2).Range("A2:A" & lastRow2)

For s1Row = 2 To lastRow1
    typeName = Sheets(SourceSheet1).Cells(s1Row, 1)
    matchCount = Application.WorksheetFunction.CountIf(rng, typeName)

    'Set the Row up on the TargetSheet. No matter if it's a match.
    Sheets(TargetSheet).Cells(tRow, 1) = typeName
    Sheets(TargetSheet).Cells(tRow, 2) = Sheets(SourceSheet1).Cells(s1Row, 2)
    Sheets(TargetSheet).Cells(tRow, 3) = Sheets(SourceSheet1).Cells(s1Row, 3)

    'Check to see if there are any matches on SourceSheet2

    If matchCount = 0 Then
    'There are NO matches.  Add Zeros to the extra columns
        Sheets(TargetSheet).Cells(tRow, 4) = 0
        Sheets(TargetSheet).Cells(tRow, 5) = 0
    Else
       'Get first matching occurance on the SourceSheet2
        m = Application.WorksheetFunction.Match(typeName, rng, 0)
        'Get Absolute Row number of that match
        s2Row = m + 1    ' This takes into account the Header Row, as index 1 is Row 2 of the search Range
        'Set the extra columns on TargetSheet to the Matches on SourceSheet2
        Sheets(TargetSheet).Cells(tRow, 4) = Sheets(SourceSheet1).Cells(s2Row, 2)
        Sheets(TargetSheet).Cells(tRow, 5) = Sheets(SourceSheet1).Cells(s2Row, 3)
    End If

    tRow = tRow + 1
Next s1Row

PHASE TWO: Checking SourceSheet2 for Entries NOT on Sheet1

Set rng = Sheets(SourceSheet1).Range("A2:A" & lastRow1)

For s2Row = 2 To lastRow2
    typeName = Sheets(SourceSheet2).Cells(s2Row, 1)
    matchCount = Application.WorksheetFunction.CountIf(rng, typeName)

    If matchCount = 0 Then
    'There are NO matches.  Add to Target Sheet
        Sheets(TargetSheet).Cells(tRow, 1) = typeName
        Sheets(TargetSheet).Cells(tRow, 2) = 0
        Sheets(TargetSheet).Cells(tRow, 3) = 0
        Sheets(TargetSheet).Cells(tRow, 4) = Sheets(SourceSheet2).Cells(s2Row, 2)
        Sheets(TargetSheet).Cells(tRow, 5) = Sheets(SourceSheet2).Cells(s2Row, 3)
        tRow = tRow + 1
    'Not doing anything for the matches, because they were already added.
    End If
Next s2Row
End Sub

EDIT: typo correction