The table T structure is as follows
COL1 col2 col3
There are repetitive records (COL1, COL2 primary key), how to delete
1, have a few repeat records (there is index on col1, COL2)
Delete T Where (Col1, Col2) in (Select Col1, Col2 from T Group By Col1, Col2 Having Count (*)> 1) And Rowid Not in (SELECT MIN (Rowid) from T Group By Col1, Col2 Having Count (* )> 1)
2, most records have repeated records
Delete T WHERE ROWID NOT IN (SELECT MIN (ROWID) from t group by col1, col2)
3, other writing
Delete t where rowid in (SELECT A.ROWID FROM T A, T B WHERE A.COL1 = B.COL1 and A.COL2 = B.COL2 and A.ROWID> B.ROWID)
