Only one entry is left for Oracle to delete duplicate data

SQL statement for Oracle query and deletion of duplicate records 1. query for redundant duplicate records in the Table. duplicate records are determined based on a single field (Id). select * from Table whereI

SQL statement for Oracle query and deletion of duplicate records 1. query for redundant duplicate records in the Table. duplicate records are determined based on a single field (Id). select * from table where I

SQL statements used to query and delete duplicate records in Oracle

1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (Id ).

Select * from table where Id in (select Id from Table group byId having count (Id)> 1)

2. Delete unnecessary duplicate records in the Table. duplicate records are determined based on a single field (Id), leaving only the records with the smallest rowid

DELETE from table WHERE (id) IN (SELECT id FROM Table group by id having count (id)> 1) and rowid not in (select min (ROWID) FROM table group by id having count (*)> 1 );

3. Search for redundant duplicate records in the table (multiple fields)

Select * from Table a where (a. Id, a. seq) in (select Id, seq from Table group by Id, seq having count (*)> 1)

4. Delete redundant record (multiple fields) in the table, leaving only the records with the smallest rowid

Delete from Table a where (. id,. seq) in (select Id, seq from Table group by Id, seq having count (*)> 1) and rowid not in (select min (rowid) from Table group by Id, seq having count (*)> 1)

5. Search for redundant duplicate records (multiple fields) in the table, excluding records with the smallest rowid

Select * from Table a where (. id,. seq) in (select Id, seq from Table group by Id, seq having count (*)> 1) and rowid not in (select min (rowid) from Table group by Id, seq having count (*)> 1)