In VFP I would create a DO WHILE loop and compare ALL columns in one table against the other table,
like this:

DO WHILE !EOF()
      SELECT TABLEB
      LOCATE TABLEB.COLUMN1 = TABLEA.COLUMN1 and TABLEB.COLUMN2 = TABLEA.COLUMN2 (and so on)
      IF FOUND()
          DELETE IN TABLEB
          DELETE IN TABLEA
     ENDIF
    SKIP IN TABLEA
ENDDO

The above is a pseudo code but maybe it will explain what I am trying to do.

>OK, I'm a little confused then. You initially said, "...just those rows that exist in one table but do not exist in another table."
>
>I took that to mean that a specific ID number was in Table A but not Table B. I guess maybe it boils down to, what is meant by "exists" in this context of the data?
>
>OK, if a single ID value (like 789) could exist as many rows in table A but not B....then you'd need to do a SELECT DISTINCT
>
>But if that doesn't help, then maybe I'm missing the question.
>
>
>>Again, thank you. The first SQL won't work since the value in ID_NUMBER could be the same for many rows. But some other columns are different. I will try your second approach. Although I thought that the SQL Select would have the actual column names.
>>
>>I am trying to figure out an example and right now I can't figure it ou.
>>
>>>Here's the simplest way....if all you want are the ID numbers in Table A that don't exist in Table B...
>>>
>>>SELECT ID_Number from TABLEA
>>>EXCEPT
>>>SELECT ID_Number from TABLEB
>>>
>>>Now, if you want "all the columns" from table A, you can do this...
>>>
>>>SELECT * FROM TABLEA WHERE ID_NUMBER IN
>>> (SELECT ID_Number from TABLEA INSIDE_A
>>> EXCEPT
>>> SELECT ID_Number from TABLEB INSIDE_B )
>>>
>>>Now....I'm assuming you don't have any NULL values for ID_Number (which, if it's a key identifier, you shouldn't).
>>>If you somehow do, you'd need to put a few IF NOT NULL statements....