mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-07 01:10:52 -04:00
Mike Bayer
4ca3092c0a
The :class:`.Alias` class and related subclasses :class:`.CTE`, :class:`.Lateral` and :class:`.TableSample` have been reworked so that it is not possible for a user to construct the objects directly. These constructs require that the standalone construction function or selectable-bound method be used to instantiate new objects. Fixes: #4509 Change-Id: I74ae4786cb3ae625dab33b00bfd6bdc4e1219139
79 lines
2.3 KiB
Python
79 lines
2.3 KiB
Python
from sqlalchemy import Column
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from sqlalchemy import column
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from sqlalchemy import Integer
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from sqlalchemy import String
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from sqlalchemy import Table
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from sqlalchemy import table
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from sqlalchemy import tablesample
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from sqlalchemy.engine import default
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from sqlalchemy.sql import func
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from sqlalchemy.sql import select
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from sqlalchemy.sql import text
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from sqlalchemy.sql.selectable import TableSample
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from sqlalchemy.testing import assert_raises_message
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from sqlalchemy.testing import AssertsCompiledSQL
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from sqlalchemy.testing import fixtures
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class TableSampleTest(fixtures.TablesTest, AssertsCompiledSQL):
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__dialect__ = default.DefaultDialect(supports_native_boolean=True)
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run_setup_bind = None
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run_create_tables = None
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@classmethod
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def define_tables(cls, metadata):
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Table(
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"people",
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metadata,
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Column("people_id", Integer, primary_key=True),
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Column("age", Integer),
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Column("name", String(30)),
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)
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def test_standalone(self):
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table1 = self.tables.people
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# no special alias handling even though clause is not in the
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# context of a FROM clause
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self.assert_compile(
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tablesample(table1, 1, name="alias"),
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"people AS alias TABLESAMPLE system(:system_1)",
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)
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self.assert_compile(
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table1.tablesample(1, name="alias"),
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"people AS alias TABLESAMPLE system(:system_1)",
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)
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self.assert_compile(
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tablesample(
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table1, func.bernoulli(1), name="alias", seed=func.random()
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),
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"people AS alias TABLESAMPLE bernoulli(:bernoulli_1) "
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"REPEATABLE (random())",
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)
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def test_select_from(self):
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table1 = self.tables.people
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self.assert_compile(
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select([table1.tablesample(text("1"), name="alias").c.people_id]),
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"SELECT alias.people_id FROM "
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"people AS alias TABLESAMPLE system(1)",
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)
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def test_no_alias_construct(self):
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a = table("a", column("x"))
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assert_raises_message(
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NotImplementedError,
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"The TableSample class is not intended to be constructed "
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"directly. "
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r"Please use the tablesample\(\) standalone",
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TableSample,
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a,
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"foo",
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)
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