doctrine/doctrine2 — pull request #273 by smoya (2012-01-26 16:44:43+00:00)
Title: No unique join column fields for Single Table inheritance type.

When we have a Single Table Inheritance, and therefore, several classes that share the same table, we dont need an unique constraint for the joincolumn field.

Example:
-------------------------------

[ Main class 'Operation' ] => [ Subclass 'Rent' ] 1 - 1 [ Class Home ]
=> [ Subclass 'Sale' ] 1 - 1 [ Class Home ]

[ Table 'Operations' ]

- id
- discr
- home_id -> we need a not unique field.
- [ ... ]