You are close. Try this instead: 
package Page;
__PACKAGE__->has_many(columns => 'Column');


package Page_column;
__PACKAGE__->has_a(page_id => 'Page');
__PACKAGE__->has_a(column_id => 'Column');


package Column;
__PACKAGE__->has_many(pages => 'Page');

[download]
And if your immediate question is "Why can columns have multiple pages", then you need to go back to your 1NF 1:N design, like kal suggested. Your second example is what i call a cross table, and the tables on the ends are the "many" relationships.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

In reply to 5Re: Class::DBI has_many by jeffa
in thread Class::DBI has_many by arc_of_descent

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