Problems with copying to the next empty row - excel

Question

I am trying to copy data from wsSource to wsDestination if the data doesn't exist in wsDestination. The data copies if the data doesn't exist but it copies to the last row rather than the next empty row.
I have attached screen shots to illustrate this
Screenshot showing data from wsDestination before any copy is done
Screenshot showing data in wsSource
Screenshot showing data in wsDestination after data has been copied
Sub test()
Dim wsSource As Worksheet, wsDestination As Worksheet
Dim LastRowSource As Long, LastRowDestination As Long
Dim i As Long, y As Long
Dim Value_1 As String, Value_2 As String, Value_3 As String
Dim ValueExists As Boolean
With ThisWorkbook
Set wsSource = .Worksheets("Data Source")
Set wsDestination = .Worksheets("Data Destination")
End With
With wsSource
'Find the last row of Column C, wsSource
LastRowSource = .Cells(.Rows.Count, "C").End(xlUp).Row
'Loop Column C, wsSource
For i = 13 To LastRowSource
'Data to be tested if it doesn't exist in wsDestination
Value_1 = .Range("B" & i).Value
Value_2 = .Range("C" & i).Value
Value_3 = .Range("D" & i).Value
ValueExists = False
With wsDestination
'Find the last row of Column B, wsDestination
LastRowDestination = .Cells(.Rows.Count, "B").End(xlUp).Row
'Loop Column B, wsDestination
For y = 5 To LastRowDestination
'Check to see whether data exists
If .Range("B" & y).Value = Value_1 Then
ValueExists = True
Exit For
End If
Next y
'If data doesn't exist in wsDestination then copy data to next available row
If ValueExists = False Then
.Range("B" & y).Value = Value_1
.Range("C" & y).Value = Value_2
.Range("D" & y).Value = Value_3
End If
End With
Next i
End With
End Sub
Screenshot 4 showing results after amended code

Answer 1

If I unterstood your problem, you always want to fill the next empty range on the destination sheet. First of all check this line:
For y = 5 To LastRowDestination
This loop will start from row number 5 which is the header row on the destination sheet. You don't want to accidentally overwrite it, so you start the loop from the 6th row like this:
For y = 6 To LastRowDestination
This line will check your rows to the last row on your destination sheet. So if every empty row has been filled, it will go to your last (not empty) row:
LastRowDestination = .Cells(.Rows.Count, "B").End(xlUp).Row
You want to check + 1 row (it will be a guaranteed empty row).
LastRowDestination = .Cells(.Rows.Count, "B").End(xlUp).Row + 1
You don't need ValueExists flag, you can check if a range is empty like this:
If WorksheetFunction.CountA(.Range("B" & y & ":D" & y)) = 0 Then ' EMPTY RANGE
So here is the cleaned up version of your code:
Sub test()
Dim wsSource As Worksheet, wsDestination As Worksheet
Dim LastRowSource As Long, LastRowDestination As Long
Dim i As Long, y As Long
With ThisWorkbook
Set wsSource = .Worksheets("Data Source")
Set wsDestination = .Worksheets("Data Destination")
End With
With wsSource
'Find the last row of Column C, wsSource
LastRowSource = .Cells(.Rows.Count, "C").End(xlUp).Row
'Loop Column C, wsSource
For i = 13 To LastRowSource
With wsDestination
'Find the last row of Column B, wsDestination
LastRowDestination = .Cells(.Rows.Count, "B").End(xlUp).Row + 1
'Data to be tested if it doesnt exist in wsDestination
'if IsError is true, data does not exist in wsDestination
If IsError(Application.VLookup(.Range("B" & i), .Range("B6:B" & LastRowDestination), 1, False)) Then
'Loop Column B, wsDestination
For y = 6 To LastRowDestination
'Check to see whether data existsd
If WorksheetFunction.CountA(.Range("B" & y & ":D" & y)) = 0 Then ' EMPTY RANGE
.Range("B" & y) = wsSource.Range("B" & i)
.Range("C" & y) = wsSource.Range("C" & i)
.Range("D" & y) = wsSource.Range("D" & i)
Exit For
End If
Next y
End If
End With
Next i
End With
End Sub