Following are the queries to remove duplicate record from a table.
SQL > select * from names;
NAME AGE ------------------------------ ---------- Alan 50 Carrie 51 Tom 52 Alan 50
rows selected.
SQL > delete from names a where rowid > (select min(rowid) from names b where b.name=a.name and b.age=a.age);
row deleted.
SQL > select * from names;
NAME AGE ------------------------------ ---------- Alan 50 Carrie 51 Tom 52
rows selected.
SQL > select * from names;
NAME AGE ------------------------------ ---------- Alan 50 Carrie 51 Tom 52 Alan 50
rows selected.
SQL > delete from names a where rowid > (select min(rowid) from names b where b.name=a.name and b.age=a.age);
row deleted.
SQL > select * from names;
NAME AGE ------------------------------ ---------- Alan 50 Carrie 51 Tom 52
rows selected.