VBA: Use one Excel Sheet to Insert to and/or Update another - vba

Question

Sheet 1 holds a full list of the current state of work orders
Sheet 2 holds recent changes to those work orders and any new work orders
Both sheets have the same format with data in columns A to L.
I need to use Sheet 2 to update the full list held in Sheet 1. Work orders have a unique identifier which is held in column A of each sheet.
In general terms:
Process each row of Sheet 2.
If a matching work order already exists in Sheet 1, update it.
If no matching work order exists in Sheet 1, add it as a new row in Sheet 1.
In column A is the work order number.

Answer 1

There may be better ways to do this, and as #Jeeped said, this has probably been asked before (though I couldn't find it). Hopefully the following is what you need. I've included lots of comments to help you understand the code and modify it should you need to.
Sub ProcessDelta()
'Define the worksheets
Dim shtDelta As Worksheet
Dim shtMaster As Worksheet
Set shtDelta = Worksheets("Sheet2")
Set shtMaster = Worksheets("Sheet1")
Dim intDeltaStartRow As Integer
'I assume there is a header row in the Delta sheet, if not, set this to 1
intDeltaStartRow = 2
Dim intMaxEverWorkOrders As Integer
'One of several ways to find the first blank row in the Master
'sheet is to start somewhere beyond the data and move up
'we use this later
intMaxEverWorkOrders = 1000000
Dim cellDeltaWorkOrder As Range
'Work order from Delta to be processed
Set cellDeltaWorkOrder = shtDelta.Cells(intDeltaStartRow, 1)
'For the destination to which we copy
Dim cellMasterWorkOrder As Range
Dim boolNewWorkOrder As Boolean
'Default to assume it's not a new workorder
boolNewWorkOrder = False
'We'll work from top to bottom in the Delta sheet. When the cell is blank we've finished
While cellDeltaWorkOrder.Value <> ""
'We're going to search for the "current" workorder from the Delta in the Master.
'If it's not there, we'll get an error. So we use "On Error" to handle it
On Error GoTo ErrorStep
'If there is no error, after the following line cellMasterWorkOrder will be the cell containing the matching workorder
Set cellMasterWorkOrder = shtMaster.Cells(WorksheetFunction.Match(cellDeltaWorkOrder.Value, shtMaster.Cells(1, 1).EntireColumn, 0), 1) '
'Reset error handling so any other errors are reported normally
On Error GoTo 0
'Check whether there was an error, if there was this was a new Workorder and needs to go at the end, so set the target cell accordingly
If boolNewWorkOrder = True Then
Set cellMasterWorkOrder = shtMaster.Cells(intMaxEverWorkOrders, 1).End(xlUp).Offset(1, 0)
boolNewWorkOrder = False 'reset this so we can check again for the next row to be processed
End If
'Output Row into Master
cellMasterWorkOrder.EntireRow.Value = cellDeltaWorkOrder.EntireRow.Value
'Move to next row in the Delta
Set cellDeltaWorkOrder = cellDeltaWorkOrder.Offset(1, 0)
Wend
'We don't want to run the error step at this point so ..
Exit Sub
ErrorStep:
'It wasn't found, which throws an error, and so it needs added as a new row.
boolNewWorkOrder = True
Resume Next
End Sub