How can I convert a string like '11-oct-2006' into a valid mysql date?

the date_format doesnot change the string in requried date format.

create table sample(name varchar(20),dat e varchar(16));
insert into sample values('java',' 11-oct-2006');

but at the time of select statement convert the string into date to change the date format like 11-10-2006.

so please help me to solve my problem....