oracle 数据库时间类型为字符串 时间范围大小查询

select  * from  invoicedetail t2 where  t2.Memo is null   and  to_char(to_date(t2.PrintDate,'yyyy-MM-dd hh24:mi:ss'), 'yyyy-MM-dd')select  * from  invoicedetail t2 where  t2.