mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-10 02:39:59 -04:00
Mike Bayer
8c0e82238c
for a select() element. The "from" calc is now delayed, so that if the construct uses a Column object that is not yet attached to a Table, but is later associated with a Table, it generates SQL using the table as a FROM. This change impacted fairly deeply the mechanics of how the FROM list as well as the "correlates" collection is calculated, as some "clause adaption" schemes (these are used very heavily in the ORM) were relying upon the fact that the "froms" collection would typically be cached before the adaption completed. The rework allows it such that the "froms" collection can be cleared and re-generated at any time. [ticket:2261] - RelationshipProperty.Comparator._criterion_exists() adds an "_orm_adapt" annotation to the correlates target, to work with the change in [ticket:2261]. It's not clear if the change to correlation+adaption mechanics will affect end user code yet. - FromClause now uses group_expirable_memoized_property for late-generated values like primary key, _columns, etc. The Select class adds some tokens to this object and has the nice effect that FromClause doesn't need to know about Select's names anymore. An additional change might be to have Select use a different group_expirable_memoized_property so that it's collection of attribute names are specific to Select though this isn't really necessary right now.
77 lines
2.4 KiB
Python
77 lines
2.4 KiB
Python
"""Generic mapping to Select statements"""
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from test.lib.testing import assert_raises, assert_raises_message
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import sqlalchemy as sa
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from test.lib import testing
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from sqlalchemy import String, Integer, select
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from test.lib.schema import Table, Column
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from sqlalchemy.orm import mapper, Session
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from test.lib.testing import eq_, AssertsCompiledSQL
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from test.lib import fixtures
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# TODO: more tests mapping to selects
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class SelectableNoFromsTest(fixtures.MappedTest, AssertsCompiledSQL):
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@classmethod
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def define_tables(cls, metadata):
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Table('common', metadata,
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Column('id', Integer, primary_key=True, test_needs_autoincrement=True),
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Column('data', Integer),
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Column('extra', String(45)))
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@classmethod
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def setup_classes(cls):
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class Subset(cls.Comparable):
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pass
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def test_no_tables(self):
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Subset = self.classes.Subset
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selectable = select(["x", "y", "z"]).alias()
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mapper(Subset, selectable, primary_key=[selectable.c.x])
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self.assert_compile(
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Session().query(Subset),
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"SELECT anon_1.x, anon_1.y, anon_1.z FROM (SELECT x, y, z) AS anon_1",
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use_default_dialect=True
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)
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def test_no_table_needs_pl(self):
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Subset = self.classes.Subset
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selectable = select(["x", "y", "z"]).alias()
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assert_raises_message(
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sa.exc.ArgumentError,
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"could not assemble any primary key columns",
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mapper, Subset, selectable
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)
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def test_no_selects(self):
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Subset, common = self.classes.Subset, self.tables.common
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subset_select = select([common.c.id, common.c.data])
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assert_raises(sa.exc.InvalidRequestError, mapper, Subset, subset_select)
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def test_basic(self):
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Subset, common = self.classes.Subset, self.tables.common
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subset_select = select([common.c.id, common.c.data]).alias()
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subset_mapper = mapper(Subset, subset_select)
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sess = Session(bind=testing.db)
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sess.add(Subset(data=1))
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sess.flush()
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sess.expunge_all()
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eq_(sess.query(Subset).all(), [Subset(data=1)])
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eq_(sess.query(Subset).filter(Subset.data==1).one(), Subset(data=1))
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eq_(sess.query(Subset).filter(Subset.data!=1).first(), None)
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subset_select = sa.orm.class_mapper(Subset).mapped_table
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eq_(sess.query(Subset).filter(subset_select.c.data==1).one(),
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Subset(data=1))
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