drop_table_if_exists.sql

CREATE OR REPLACE PROCEDURE drop_table_if_exists(tableName VARCHAR2)
IS
  table_nums NUMBER(2);
BEGIN
     SELECT COUNT(1) INTO table_nums FROM user_tables WHERE table_name=UPPER(tableName);
     IF table_nums > 0 THEN
        EXECUTE IMMEDIATE 'DROP TABLE ' || tableName || ' CASCADE CONSTRAINTS';
     END IF;
END;
/