[Dbix-class] Schema design query

[Dermot]

Hi,

I am trying to design a schema and I could use some ideas as I'm not
confident about the best way forward.

I have a table of entities. Each entity is to belong to at least one
or more of 7 different categories. The requirement is to retrieve
entities by category. As far as I can tell, I either include a new
field in the entities table (is_cat1, is_cat2...etc) or I create one,
or possibly, more join tables on the entities and their category. The
other issue is that user's search the entities table via a web
front-end search facility (not from the DB) that returns the entity
id,  so I am trying to find a structure that, given a entity_id, can
be filtered on relationship to the categories.

Sorry I know this isn't directly related to DBIx (yet) but any
suggestions would be appreciated.
Thanx.
Dp.