[CDBI] How find_or_create method handle float data type?

Hi there,

I'm new to Class::DBI, and have a question. How can I use find_or_create method
if I have columns with float data type? 
my $id = DB::MySQLDb::MyTable->find_or_create({ float_column => 2.01})
doesn't work, it returns a new id every time I run it. In mysql sql statement, I
could do "select * from mytable where float_column - 2.01 < 0.001", how about
using Class-DBI?
Thanks!

David