mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-15 21:27:23 -04:00
Mike Bayer
42 lines
1.3 KiB
Python
42 lines
1.3 KiB
Python
from sqlalchemy import *
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import sqlalchemy.attributes as attributes
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engine = create_engine('sqlite://', echo=True)
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class Tree(object):
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def __init__(self, name='', father=None):
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self.name = name
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self.father = father
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def __str__(self):
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return '<TreeNode: %s>' % self.name
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def __repr__(self):
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return self.__str__()
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table = Table('tree', engine,
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Column('id', Integer, primary_key=True),
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Column('name', String(64), nullable=False),
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Column('father_id', Integer, ForeignKey('tree.id'), nullable=True),)
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assign_mapper(Tree, table,
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properties={
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# set up a backref using a string
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#'father':relation(Tree, foreignkey=table.c.id,primaryjoin=table.c.father_id==table.c.id, backref='childs')},
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# or set up using the backref() function, which allows arguments to be passed
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'childs':relation(Tree, foreignkey=table.c.father_id, primaryjoin=table.c.father_id==table.c.id, backref=backref('father', uselist=False, foreignkey=table.c.id))},
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)
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table.create()
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root = Tree('root')
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child1 = Tree('child1', root)
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child2 = Tree('child2', root)
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child3 = Tree('child3', child1)
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objectstore.commit()
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print root.childs
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print child1.childs
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print child2.childs
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print child2.father
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print child3.father
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