How to detect duplicate records of field values in the same table

MySQL query duplicate records a lot of ways, below to introduce you to several of the most commonly used MySQL query duplicate record method, I hope that you learn MySQL query duplicate records can help.

1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to judge

SELECT * from People   

2, delete redundant records in the table, duplicate records are based on a single field (Peopleid) to judge, leaving only rowid minimal records

Delete from people   
where Peopleid on (select Peopleid from People GROUP by Peopleid have   count (Peopleid) > 1) and rowID not in   
(select min (rowid) from people GROUP by Peopleid have Count (Peopleid) >1)   

3. Find redundant records in the table (multiple fields)

SELECT * from Vitae a   
where (A.PEOPLEID,A.SEQ) in (select Peopleid,seq to Vitae GROUP by PEOPLEID,SEQ has count (* ) > 1)   

4, delete redundant records in the table (multiple fields), leaving only the smallest ROWID records

Delete from Vitae a   
where (A.PEOPLEID,A.SEQ) in (select Peopleid,seq to Vitae GROUP by PEOPLEID,SEQ have count (*) > 1) and rowID not in   
(select min (rowid) from Vitae GROUP by PEOPLEID,SEQ have Count (*) >1)  

5, look for redundant records in the table (multiple fields), does not contain the smallest ROWID records

SELECT * from Vitae a   
where (A.PEOPLEID,A.SEQ) in (select Peopleid,seq to Vitae GROUP by PEOPLEID,SEQ has count (* ) > 1) and rowID not in   
(select min (rowid) from Vitae GROUP by PEOPLEID,SEQ have Count (*) >1)