DataMapper ORM v1.8.2

[eluser]WanWizard[/eluser]
So, to check if I understand it correct:

RealEstate has_many Position, Position has_many RealEstate (as an owner can have multiple properties?)
Position has_many Client, Client has_many Position (something can have multiple owners, a client can own multiple properties?)

So far so good? If so, nothing special about this design.

So you need to create three models, for RealEstate, Position and Client. You will need table 'realestates', 'positions' and 'clients' for those models (tables are plural and lowercase).

To create the many-to-many, a relation table (or join table, or junction table) is required, which Datamapper constructs from the table names of both models in the relation. In this case, you need relation tables called 'clients_positions' and 'positions_realestates' as they are joined an alphabetical order.

'clients_positions' should contain the columns 'id', 'client_id' and 'position_id', 'positions_realestates' should contain the columns 'id', 'position_id' and 'realestate_id'.

This should be it. The models themselfs are simple, no advanced stuff needed, this is a basic Datamapper design.