删除数据库一个用户下的所有对象.
DECLARE

Drop_Cmd VARCHAR(200);
CURSOR Cur_Objects IS
SELECT 'drop table ' || Table_Name || ' CASCADE CONSTRAINTS '
FROM User_Tables
UNION ALL

SELECT 'drop view ' || View_Name || ' CASCADE CONSTRAINTS '
FROM User_Views
UNION ALL

SELECT 'DROP FUNCTION ' || Object_Name
FROM User_Objects o
WHERE o.Object_Type = 'FUNCTION'

UNION ALL
SELECT 'drop SEQUENCE ' || SEQUENCE_Name || ' '
FROM User_Sequences;
BEGIN

--disable all
OPEN Cur_Objects;
LOOP
FETCH Cur_Objects
INTO Drop_Cmd;
EXIT WHEN Cur_Objects%NOTFOUND;

EXECUTE IMMEDIATE Drop_Cmd;
END LOOP;

CLOSE Cur_Objects;

END;