Macro to Compare Two Columns of Numbers on Two Sheets and Flag Mat

[Ezra]

I have a worksheet ("All SEG ISBNs") which is a long list of numbers in
Column E. I have another sheet "WH ISBNs") in the same workbook with a long
list of numbers in Column A. Is it possible to write a macro that will take
each one of the numbers on the "WH ISBNs" sheet, look for it on the "All SEG
ISBNs" sheet, and, if it finds a match on the "All SEG ISBNs" sheet, add the
text "WH Match Found" next in Column F on the "All SEG ISBNs" sheet--that is,
next to each of the matching numbers? There may be duplicate numbers in each
column on each sheet, and it's OK if the macro inserts "WH Match Found" next
to each occurrence. (By the way, both sheets have header rows.)

I've used the COUNTIF function to identifying matching numbers, but it seems
to take a very long time to calculate. If was hoping that a macro-based
version would be faster, and besdies, I'm hoping to do this same thing for
other sheets in the same workbook, and the calculation time for a
formula-based solution is just going to get worse and worse.

I've poked about and found various macros that seem to come close to what I
need, but frankly, I'm not knowledgeable enough to manipulate them well, and
my various attempt to loop and whatnot keep ending in disaster.

Any help would be much, much appreciated!

 

[Bernie Deitrick]

Ezra,

A formula based solution should be extremely fast - in fact, if I were to write the macro, I would
use the code to write a column of formulas, calculate the formulas, and then copy and convert them
to values. That is typically much faster than looping through with code.

You may simply want to limit the number of formulas that you use, or the range that you compare, or
you could copy the column of formulas, then paste special values, and that will eliminate the
re-calc issue.

Or post your formula - there may be ways to make it better....

HTH,
Bernie
MS Excel MVP

 

[JLGWhiz]

Try this:

Sub matchemup()
Dim ws1 As Worksheet, ws2 As Worksheet, rng As Range
Dim lr As Long
Set ws1 = Worksheets("All SEG ISBNs")
Set ws2 = Worksheets("WH ISBNs")
lr = ws1.Cells(Rows.Count, 5).End(xlUp).Row
lr2 = ws2.Cells(Rows.Count, 1).End(xlUp).Row
Set rng = ws1.Range("E2:E" & lr)
For Each c In rng
For i = 2 To lr2
If c.Value = ws2.Cells(i, 1).Value Then
c.Offset(, 1) = "WH Match Found"
End If
Next
Next
End Sub

 

[Ezra]

Hi, Bernie:

I've pared down my formula as much as possible--in fact, out of desperation,
it's almost nothing now. In Column F on the "All SEG ISBNs" sheet, I have
this in each cell:

=COUNTIF('WH ISBNs'!$A2:$A6000,=E2)

Originally, I had this embedded in an IF function that would replace the
number returned into with the text string "WH Match Found" if the number
returned was greater than zero. Even going with this pared-down version,
though, which just gives me the raw count of matching numbers, it was taking
about ten minutes to calculate. I can set the calculation mode to manual and
just calulcate when I'm ready to do so, but I always hate doing that unless I
absolutely have to.

The "All SEG ISBNs" sheet is about 40,000 rows deep, and the "WH ISBNs"
sheet is about 5000 rows, and I know that the various IF functions always
take slightly longer to calculate, but this is just nutty. The results it
generates are fine, but this thing is updated in varying ways often, and the
calc time issue is driving users crazy. (Users are on both PCs and Macs in
our office, but the calc time is long on both platforms, and I don't have
reason to believe that workstation capacity is impeding crunch time in a
significant way.)

If there's a much faster way to do this, I'd really appreciate any
suggestions to can offer. Thanks!

 

[Ezra]

I appreciate the code, JLGWhiz! Unfortunately, it seems to keep getting stuck
in a loop somewhere. That is, it starts up and doesn't error out, but it
never stops running. I've made sure there aren't any blank cells in either of
the columns being compared, but that doesn't seem to make a difference--it
just keeps on going, with the result that I have to (on a Mac) do a Force
Quit to pull out.

If you have any more ideas, I'd really appreciate it--certainly, I
appreciate what both you and Bernie (above) have contributed so far!

Ezra

 

[Dave Peterson]

I would use the worksheet formula =match() instead (I bet it's quicker than
=countif()). I could use a formula like:

=isnumber(match(e2,'wh isbns'!a:a,0))

It would return TRUE if there's a match and False if there is no match.

In fact, I'd do it manually instead of using a macro.

But if I needed a macro, I wouldn't do the =match() in code, I'd populate the
range with formulas that did the work.

This puts the formula in, converts to values, removes the false's and changes
the true's to your text. (I would have lived with the true/false.

Option Explicit
Sub Testme()

Dim myRng As Range
Dim myLookupRng As Range

With Worksheets("all seg isbns")
Set myRng = .Range("E2", .Cells(.Rows.Count, "E").End(xlUp))
End With

With Worksheets("wh isbns")
Set myLookupRng = .Range("a:a")
End With

With myRng.Offset(0, 1)
.FormulaR1C1 _
= "=isnumber(match(rc[-1]," _
& myLookupRng.Address(external:=True, _
ReferenceStyle:=xlR1C1) _
& ",0))"

'application.calculate 'are you still in manual calc mode???

.Value = .Value

.Replace what:=False, _
replacement:="", _
lookat:=xlWhole, _
searchorder:=xlByRows, _
MatchCase:=False
.Replace what:=True, _
replacement:="WH Match Found", _
lookat:=xlWhole, _
searchorder:=xlByRows, _
MatchCase:=False

End With
End Sub

 

[JLGWhiz]

Although it worked in a test set up, it looks as though you have enough
suggestions to play with for a while, so I will move on.