I have a table that I need to identify duplicate entries based off the value of a single column, and delete all but one of the duplicate entry records.

Was hoping someone had a routine already for something like this. I found this example, but it doesn't work, gives error on the where (patientID,mpinumber) line:

delete from patients
  where (PatientID, mpinumber) 
    not in
    ( select min(PatientID), mpinumber
         from patients group by mpinumber)

Thanks

Kirk