[SQLObject] Information about the restrictions of foreign keys

[Luc S. <luc...@ad...>]

Hello,

I'm trying to understand how SQLObject works, but I'm having problem 
understanding the generated tables:

If I want to create two tables, with one that has a relation one-to-many to 
the other, I define an attribute with the ForeignKey() method, but when I do 
this, I notice that there are no *real* restriction on the usage of that 
generated column in the database (I'm using PostgreSQL). Here are more 
explanations:

Let's take two example tables/classes:

=======
class societe(SQLObject):
    _connection = conn
    _columns=[
        StringCol('socNom', length=20, alternateID=True,
                       notNull=1,unique=True),
        StringCol('socMail', length=50, unique=True),
        ]
    secteurRegies = MultipleJoin('secteurRegie')

class secteurRegie(SQLObject):
    _connection = conn
    _columns=[]
    societe = ForeignKey('societe')

societe.createTable()
secteurRegie.createTable()
=======
Here are the created tables in PostgreSQL:
Query   : CREATE TABLE societe (
    id SERIAL PRIMARY KEY,
    soc_nom VARCHAR(20) NOT NULL UNIQUE,
    soc_mail VARCHAR(50) UNIQUE,
)
Query   : CREATE TABLE secteur_regie (
    id SERIAL PRIMARY KEY,
    societe_id INT
)
=======
And nothing more ! I would have expected that SQLObject would define 
societe_id to be a foreign key to societe.id.
That means I can do INSERTs in secteur_regie with non-existent societe_id 
values. That bothers me a lot.
I guess this is not too important if I'm using *only* SQLObject, but I'm 
accessing/INSERTing data from other sources programs, and I want to be sure 
that I don't have any incoherent data (and, btw, use the 'ON DELETE CASCADE' 
to remove automatically deleted records).

So, to summarize, Is it possible to implement a code like this:

ALTER TABLE secteur_regie
        ADD FOREIGN KEY (societe_id)
        REFERENCES societe (id) ON UPDATE CASCADE ON DELETE CASCADE;


Or maybe I haven't  understood how to declare foreign keys?

Thanks for your help,
Luc Stepniewski
-- 
Luc Stepniewski <ls...@ad...> <http://lstep.free.fr/>
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