pg_atoi error

Hello,

In my query:
select * from experimentinfo where expid='1';
here data type of expid is int.
My question is:
if I change expid ='xyz', error is: pg_atoi: error
in "xyz": can't parse "xyz"
if I change expid ='', error is: pg_atoi:
zero-length string

In mysql, seems this will not happen and will give
you 0 row result. but not error message.

So, How can I avoid these annoying message?

Regards,
William