sql - Oracle Date comparison issue -

i have table dates, there weird it.

when query table

select distinct process_dt table;

the output : 11/16/2013

when query table

select process_dt table  process_dt=to_date('20131116', 'yyyymmdd');

the output 0 records.

when query table

select process_dt table  process_dt=trunc(process_dt);

the output give 100 rows, 11/16/2013.

i not understanding why second query not working. idea? should change session in way?

the problem current check date data type contains time. need use trunc date column make work.

KBPS