Class::DBI and Ima::DBI and ints and objects

[rkg]

Hi folks --

I'm using Class::DBI, and I need an aggregate function, so as per the docs I'm using set_sql, as Class::DBI inherits from Ima::DBI. This works fine

Rk::M->set_sql(maxid => q(select max(m) from m)); 
my $sth = Rk::M->sql_maxid;
$sth->execute;
my ($max) = $sth->fetchrow_array;

However, the Class::DBI docs indicate this shorter form might work too:

Rk::M->set_sql(maxid => q(select max(m) from m)); 
my $max = Rk::M->maxid;

It doesn't, complaining it can't locate object method 'maxid' via package Rk::M.

Am I reading the docs wrong here? I get the sense Class::DBI always wants to return a Rk::M (or whatever) object, not a simple int, but perhaps that's a second problem here -- for now, I am wondering why Class::DBI isn't even executing the method.

Thanks for your advice.

rkg