I'm trying to explicitly save/delete objects, and I ran into a snag with objectstore.delete().
# it gets no more generic than this
a_table = Table('a',
Column('a_id', Integer, Sequence('next_a_id'), primary_key=True),
Column('a', String(10)),
Column('b',String(20)),
Column('c',String(64)),
Column('d',Integer))
b_table = Table('b',
Column('b_id',Integer,Sequence('next_b_id'),primary_key=True),
Column('a_id',Integer,ForeignKey('a.a_id')),
Column('b',String(10)))
class A(object):pass
class B(object):pass
B.mapper = mapper(B,b_table)
A.mapper = mapper(A,a_table,properties= {'bs' : relation(B.mapper,private=True)})
A.mapper.table.create()
B.mapper.table.create()
# create some objects
a = A()
a.bs = []
a.a = 'heyhey'
a.b = 'pokey'
# add a 'B' instance
b = B()
b.b = '1111'
a.bs.append(b)
# add another one
b = B()
b.b = '2222'
a.bs.append(b)
engine.begin()
# inserts both A and Bs
objectstore.commit(a)
objectstore.delete(a)
objectstore.commit(a) # deletes only instance of 'A', not children -> foreign key exception
engine.commit()
(this is run against a postgres database)
Is this a bug or am I doing something wrong? I was very pleased to find this ability to explicitly issue the sql statements for a give graph of objects, and in fact, solves most of the issues that I've come across with sqlalchemy. The combination of objectstore.commit/delete/remove for a given object is really useful, particularly if you need the identifiers for the objects you are creating around the same time as you instantiate them (logging, etc), and you don't have to worry about sequences v. autoincrement.
Aaron Bickell
