9i里的convert()函数
我想把last_answer_time日期型转换为varchar2,怎么不行啊? 
 convert(varchar2(10),last_answer_time,120) 
 last_answer_time是字段名
------解决方案--------------------select cast(hire_date as varchar2(30)) from employees; 
 or 
 select to_char(hire_date) from employees;