Yes, if you added that AUTO_INCREMENT field.
Say you named it "uniqueid".
FROM tablename AS t1, tablename AS t2
WHERE t1.lnktxt = t2.lnktxt
AND t1.cattxt = t2.cattxt
AND t1.datetxt = t2.datetxt
AND t1.uniqueid < t2.uniqueid
But run the other query first, so that you get rid of the ones that *DO* differ by date. And only then run this one as a sort of cleanup.