the foreign key between table2 and their children was wrong.. now
works correctly.
Thanks for your help!
greetings,
Fernando
table_21 = \
Table(
'table_21', metadata,
Column('id2', Integer, primary_key = True),
Column('info', String),
ForeignKeyConstraint(['id2'],['table_2.id2']),
)
table_22 = \
Table(
'table_22', metadata,
Column('id2', Integer, primary_key = True),
Column('ext', Integer, nullable = False),
Column('info', String),
ForeignKeyConstraint(['id2'],['table_2.id2']),
ForeignKeyConstraint(['ext'],['table_ex22.id'])
)
On 18 mayo, 23:51, Michael Bayer <mike...@zzzcomputing.com> wrote:
> try taking a look at your SQL output. the issue is pretty obvious,
> the join condition between your two tables is insufficient to get a
> T22 row. table_2.id has two rows with "0" for the "id" column, so
> joining from table_2 to table_22 on just "id" gives you two rows. it
> has nothing to do with the relation() or anything else.
>
> On May 18, 2009, at 3:59 PM, fleong wrote:
>
> > from sqlalchemy import *
> > from sqlalchemy.orm import *
>
> > engine = create_engine('sqlite:///',echo = True)
>
> > metadata = MetaData()
>
> > table_1 = \
> > Table(
> > 'table_1', metadata,
> > Column('id', Integer, primary_key = True),
> > )
>
> > table_2 = \
> > Table(
> > 'table_2', metadata,
> > Column('id', Integer, primary_key = True),
> > Column('id2', Integer, primary_key = True),
> > Column('type', Integer, nullable = False),
> > ForeignKeyConstraint(['id'],['table_1.id'])
> > )
>
> > table_21 = \
> > Table(
> > 'table_21', metadata,
> > Column('id', Integer, primary_key = True),
> > Column('id2', Integer, primary_key = True),
> > Column('info', String),
> > ForeignKeyConstraint(['id'],['table_2.id']),
> > )
>
> > table_22 = \
> > Table(
> > 'table_22', metadata,
> > Column('id', Integer, primary_key = True),
> > Column('id2', Integer, primary_key = True),
> > Column('ext', Integer, primary_key = True),
> > Column('info', String),
> > ForeignKeyConstraint(['id'],['table_2.id']),
> > ForeignKeyConstraint(['ext'],['table_ex22.id'])
> > )
>
> > table_ex22 = \
> > Table(
> > 'table_ex22', metadata,
> > Column('id', Integer, primary_key = True),
> > )
>
> > class Table1(object):
> > pass
>
> > class Table2(object):
> > pass
>
> > class Table21(Table2):
> > pass
>
> > class Table22(Table2):
> > pass
>
> > class TableEx22(object):
> > pass
>
> > mapper(Table1, table_1,
> > properties = {\
> > 't2': relation(Table2, backref = 't1', cascade = 'all, delete,
> > delete-orphan', passive_updates = False, passive_deletes = False),
> > }
> > )
> > mapper(TableEx22, table_ex22,
> > properties = {\
> > 't22': relation(Table22, backref = 'tex', cascade = 'all,
> > delete, delete-orphan', passive_updates =False, passive_deletes =
> > False),
> > }
> > )
> > mapper(Table2, table_2, polymorphic_on=table_2.c.type,
> > polymorphic_identity=0)
> > mapper(Table21, table_21, inherits=Table2, polymorphic_identity=1)
> > mapper(Table22, table_22, inherits=Table2, polymorphic_identity=2)
>
> > Session = sessionmaker()
> > #------------------------------------------------------------------------------
>
> > #test:
>
> > metadata.bind = engine
> > metadata.create_all()
>
> > s = Session()
>
> > t = Table1()
> > t.id = 0
>
> > tex = TableEx22()
> > tex.id = 0
>
> > s.add(t)
> > s.add(tex)
> > s.commit()
>
> > t21 = Table21()
> > t21.id2 = 0
> > t21.t1 = t
> > s.add(t21)
> > s.commit()
>
> > t22 = Table22()
> > t22.id2 = 1
> > t22.t1 = t
> > t22.tex = tex
> > s.add(t22)
> > s.commit()
>
> > for i in tex.t22:
> > print type(i)
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