Comparing 2 columns and deleting duplicates in the second column according first column

I've looked all over the place for hours trying to find this answer with no success. It seems simple, but apparently is not

In general, this is what I'm trying to do:

I want to find values in a second column that are duplicates of values in the first column, and delete those second column duplicates Without deleting the duplicates (which do exist) in the first column. I've tried it all, and have only figured out about 300 ways that Do Not work. Hopefully someone here can figure out one way this Will work!

thanks in advance
-Ryan

Here is a small sample of a much, much larger spreadsheet. If you look at the spreadsheet, you'll notice 3 columns - 2 with Parcel IDs and 1 with the "API No." Notice that there are frequently multiple API #s per parcel ID. I bring this data into excel via highly complex mapping software as two separate data sets. One data set contains all parcels within a one mile radius of a certain "subject parcel." The second data set contains every oil well located within a one mile radius of the "subject parcel" along with the parcel ID that the well is located. All too often, much of this data overlaps.

Without getting too in depth, and since this data is imported as two separate sets with overlapping contents, I need a way to identify values in the "Parcels 1" column that are duplicates of any number in the "Parcels 2" column and delete them - without affecting data from the "Parcels 2" column.

Good luck to us all on this one!

thanks

Hi wingo,

Here's my take... it's a 4 step process, but it seems to work on my end...

Let me know if you don't understand...

Take care,
Dennis

Djapigo,

Thanks for the response. There seems to be a problem with the uploaded file in your post, it keeps saying file is corrupted when I try to open it - do you think you can re-upload it for me?

thanks

Hi wingo033

if you do a search on this site, this subject has been discussed a few times. Here's a couple of links.

http://www.excelforum.com/excel-gene...ne-column.html

http://www.cpearson.com/excel/Duplicates.aspx

Dennis, thanks for the effort. I''m not sure I understand it completely because I can't get it to work. Essentially, I need any number in column 1 that is a duplicate of any number in column 2 deleted automatically (but leaving column 2 untouched). The formula you provided doesn't seem to do that, however the fault could definitely be my own here. I'm looking for something that will automatically delete my target duplicates in column 1, as anything other than automatic will take weeks/months (there are over 30,000 entries). I'm kinda lost on your suggestion, sorry about that

That's too bad... I suggest you check Kevin's suggestion... someone posted some VBA coding that seems to work... good luck...

Well, using the MATCH function as noted in one of the links Kevin suggested, I got it to work. It seems like a very roundabout way of accomplishing what I want, but I guess it gets the job done.