SQL deletes duplicate records and retains one of the

SQL: Delete duplicate data, keep only one with SQL statement, delete duplicates only keep one in thousands of records, there are some identical records, how to use SQL statements, delete duplicates

1. Find redundant duplicate records in the table, duplicate records are based on a single field (Peopleid) to determine the select * from people where Peopleid in (select Peopleid from people GROUP by people Id having count (Peopleid) > 1)

2, delete redundant records in the table, duplicate records are based on a single field (Peopleid) to judge, leaving only the rowID minimum record delete from people where peoplename in (select Peoplename from P Eople GROUP BY Peoplename have count (peoplename) > 1) and Peopleid not in (select min (Peopleid) from people GR OUP by Peoplename have count (peoplename) >1)

3. Find redundant duplicate records in the table (multiple fields) SELECT * from Vitae a WHERE (A.PEOPLEID,A.SEQ) in (select Peopleid,seq from Vitae GROUP by Peopleid,se Q Having COUNT (*) > 1)

4. Delete redundant duplicate records (multiple fields) in the table, leaving only the rowID minimum record delete from Vitae a where (A.PEOPLEID,A.SEQ) in (select Peopleid,seq from 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. Find redundant duplicate records in the table (multiple fields), does not contain ROWID minimum records select * from Vitae a WHERE (A.PEOPLEID,A.SEQ) in (select Peopleid,seq from Vitae group by PEOPLEID,SEQ have count (*) > 1) and rowID not in (select min (rowid) from Vitae GROUP by PEOPLEID,SEQ have count ( *) >1)

6. Remove the first bit to the left of a field:

Update TableName Set [Title]=right ([title], (Len ([title])-1)) where Title like ' Village% '

7. Remove the first bit to the right of a field:

Update TableName Set [Title]=left ([title], (Len ([title])-1)) where Title like '% Village '

8. False delete redundant duplicate records in table (multiple fields), does not contain ROWID minimum records update vitae set ispass=-1 where Peopleid in (select Peopleid from Vitae GROUP by peopl EID,SEQ have count (*) > 1) and seq in (select seq from vitae GROUP by PEOPLEID,SEQ have count (*) > 1) and rowID Not in (select min (rowid) from Vitae GROUP by PEOPLEID,SEQ have Count (*) >1)

SQL deletes duplicate records and retains one of the