This may works.
SELECT PERSON.PERSON_ID, COUNT(PERSON.SOC_SEC_NO) FROM PERSON HAVING COUNT(PERSON.SOC_SEC_NO) > 1; From: firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com] Sent: quinta-feira, 4 de fevereiro de 2016 17:10 To: firebird-support@yahoogroups.com Subject: [firebird-support] How do find duplicates in a table? Greetings All, How do I form a SQL Select statement that will return which records in my PERSON table have duplicate SOC_SEC_NO. In other words I need a list of persons where the social security number appears in the database more than once. Some SOC_SEC_NO may be null which I do not care about. PERSON: PERSON_ID SOC_SEC_NO Any help appreciated, Mike
