mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-11 03:10:38 -04:00
Mike Bayer
42 lines
1.1 KiB
Python
42 lines
1.1 KiB
Python
from sqlalchemy import *
|
|
|
|
metadata = BoundMetaData('sqlite:///', echo=True)
|
|
|
|
class Tree(object):
|
|
def __init__(self, name='', father=None):
|
|
self.name = name
|
|
self.father = father
|
|
def __str__(self):
|
|
return '<TreeNode: %s>' % self.name
|
|
def __repr__(self):
|
|
return self.__str__()
|
|
|
|
table = Table('tree', metadata,
|
|
Column('id', Integer, primary_key=True),
|
|
Column('name', String(64), nullable=False),
|
|
Column('father_id', Integer, ForeignKey('tree.id'), nullable=True))
|
|
table.create()
|
|
|
|
mapper(Tree, table,
|
|
properties={
|
|
'childs':relation(Tree, remote_side=table.c.father_id, primaryjoin=table.c.father_id==table.c.id, backref=backref('father', remote_side=table.c.id))},
|
|
)
|
|
|
|
root = Tree('root')
|
|
child1 = Tree('child1', root)
|
|
child2 = Tree('child2', root)
|
|
child3 = Tree('child3', child1)
|
|
|
|
child4 = Tree('child4')
|
|
child1.childs.append(child4)
|
|
|
|
session = create_session()
|
|
session.save(root)
|
|
session.flush()
|
|
|
|
print root.childs
|
|
print child1.childs
|
|
print child2.childs
|
|
print child2.father
|
|
print child3.father
|