Oracle时间格式转换&模糊查询

SQL> select to_char(to_date('2002-1-1 12:12:12','yyyy-mm-dd hh24:mi:ss'),'yyyy-mm-dd hh24:mi:ss') from dual;

TO_CHAR(TO_DATE('20
-------------------
2002-01-01 12:12:12

SQL> select username from userinfo where username like '%j%';

select sysdate from dual;