How to find duplicate records in a table? MySQL or SQL Query to find duplicates in a table suppose you have a table like this which represent some user transactions: Table Name : tbl_user_trans transId userId transDate transAmount 1000 USR034 2012-01-01 300.25 1001 USR004 2012-01-08 100.05 1002 USR030 2012-01-11 30.59 1003 USR034 2012-01-08 1000.65 1004 USR050 2012-02-01 19.25 1005 USR034 2012-02-03 403.25 If want to find all Users from the transaction table who had made transactions more than once , then you have to do like this: SELECT userId, COUNT(userId) AS HowMany FROM tbl_user_trans GROUP BY userId HAVING ( COUNT(userId) > 1 ) The query will return userId HowMany USR034 ...