SQL> desc test Name Null? Type ----------------------------------------- -------- ----------------- ID NUMBER --表 test有重復的記錄1,10 SQL> select * from test; ID ---------- 1 2 3 4 10 1 1 1 1 1 1011 rows selected. --查詢表中的哪些記錄有重復 SQL> select * from test group by id having count(*)>1; ID ---------- 1 10 --查詢出沒有重復記錄的結果集 SQL> select * from test group by id; ID ---------- 1 2 3 4 10SQL> select distinct * from test; ID ---------- 1 2 3 4 10 --刪除重復的記錄 SQL> delete from test a where a.rowid!=(select max(rowid) from test b 2 where a.id=b.id);6 rows deleted.SQL> commit;Commit complete. --刪除后的查詢結果集 SQL> select * from test; ID ---------- 2 3
