mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-06-01 05:18:44 -04:00
Mike Bayer
065fcbd9d2
relationship(), to eliminate confusion over the relational algebra term. relation() however will remain available in equal capacity for the foreseeable future. [ticket:1740]
94 lines
2.8 KiB
Python
94 lines
2.8 KiB
Python
import testenv; testenv.simple_setup()
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from sqlalchemy import *
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from sqlalchemy.orm import *
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from timeit import Timer
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import sys
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meta = MetaData()
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orders = Table('orders', meta,
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Column('id', Integer, Sequence('order_id_seq'), primary_key = True),
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)
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items = Table('items', meta,
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Column('id', Integer, Sequence('item_id_seq'), primary_key = True),
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Column('order_id', Integer, ForeignKey(orders.c.id), nullable=False),
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)
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attributes = Table('attributes', meta,
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Column('id', Integer, Sequence('attribute_id_seq'), primary_key = True),
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Column('item_id', Integer, ForeignKey(items.c.id), nullable=False),
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)
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values = Table('values', meta,
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Column('id', Integer, Sequence('value_id_seq'), primary_key = True),
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Column('attribute_id', Integer, ForeignKey(attributes.c.id), nullable=False),
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)
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class Order(object): pass
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class Item(object): pass
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class Attribute(object): pass
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class Value(object): pass
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valueMapper = mapper(Value, values)
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attrMapper = mapper(Attribute, attributes, properties=dict(
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values=relationship(valueMapper, cascade="save-update", backref="attribute")
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))
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itemMapper = mapper(Item, items, properties=dict(
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attributes=relationship(attrMapper, cascade="save-update", backref="item")
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))
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orderMapper = mapper(Order, orders, properties=dict(
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items=relationship(itemMapper, cascade="save-update", backref="order")
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))
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class TimeTrial(object):
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def create_fwd_assoc(self):
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item = Item()
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self.order.items.append(item)
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for attrid in range(10):
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attr = Attribute()
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item.attributes.append(attr)
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for valueid in range(5):
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val = Value()
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attr.values.append(val)
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def create_back_assoc(self):
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item = Item()
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item.order = self.order
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for attrid in range(10):
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attr = Attribute()
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attr.item = item
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for valueid in range(5):
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val = Value()
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val.attribute = attr
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def run(self, number):
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s = create_session()
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self.order = order = Order()
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s.save(order)
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ctime = 0.0
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timer = Timer("create_it()", "from __main__ import create_it")
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for n in xrange(number):
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t = timer.timeit(1)
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print "Time to create item %i: %.5f sec" % (n, t)
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ctime += t
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assert len(order.items) == 10
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assert sum(len(item.attributes) for item in order.items) == 100
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assert sum(len(attr.values) for item in order.items for attr in item.attributes) == 500
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assert len(s.new) == 611
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print "Created 610 objects in %.5f sec" % ctime
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if __name__ == "__main__":
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tt = TimeTrial()
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print "\nCreate forward associations"
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create_it = tt.create_fwd_assoc
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tt.run(10)
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print "\nCreate backward associations"
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create_it = tt.create_back_assoc
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tt.run(10)
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