Hi all, I have a mapper that looks like this:
mapper( Registration, registration_table, properties={
'purchase': relation(Purchase,
backref=backref('registration', uselist=False),
cascade='all' ),
})
My registration table has a foreign key to purchases, and I want to make
sure no registration exists without an associated purchase. I have the
referrence backwards like a many-to-one because purchases may also be
referred to in other tables ( like memberships ). Maybe this is not a
good idea, not sure. Feel free to tell me. Should this perhaps be
handled in a separate associating table with primary key with one column
primary key constraints on it?
But, my immediate problem is that I don't know what the correct way to
make sure I create a purchase on creation of a registration. Should I be
creating a purchase in the registration constructor? Should I be doing
something like:
r = Registration( purchase=Purchase() )
Or should it work magically if I set up my cascade options differently?
Thanks
Iain
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