[eluser]NachoF[/eluser]
I remember I tried it some time ago and the problem I ran into was with the foreign keys....cause sometimes datamapper inserts something with null values and then automatically updates it(Im sure you know more about that than I do).. so if your database has foreign key constraints this will fail...the other thing is that if you have id, employee_id, department_id then all THREE would have to be primary keys cause otherwise how would you do auto_incremented on id if its not primary??... but if it IS primary then we have the same vulnerability cause you could do
deparments_employees
===================================
id | employee_id |department_id |
---+-----------------+-------------+
1 | 1 | 2 |
2 | 1 | 2 |
and again have the same employee related to the same department twice cause it has a different id.... what a pickle.