import sqlalchemy as sa
from sqlalchemy import Column
from sqlalchemy import Integer
from sqlalchemy import MetaData
from sqlalchemy import Table
from ._autogen_fixtures import AutogenFixtureTest
from ... import testing
from ...testing import config
from ...testing import eq_
from ...testing import exclusions
from ...testing import is_
from ...testing import is_true
from ...testing import mock
from ...testing import TestBase
class AutogenerateComputedTest(AutogenFixtureTest, TestBase):
__requires__ = ("computed_columns",)
__backend__ = True
def test_add_computed_column(self):
m1 = MetaData()
m2 = MetaData()
Table("user", m1, Column("id", Integer, primary_key=True))
Table(
"user",
m2,
Column("id", Integer, primary_key=True),
Column("foo", Integer, sa.Computed("5")),
)
diffs = self._fixture(m1, m2)
eq_(diffs[0][0], "add_column")
eq_(diffs[0][2], "user")
eq_(diffs[0][3].name, "foo")
c = diffs[0][3].computed
is_true(isinstance(c, sa.Computed))
is_(c.persisted, None)
eq_(str(c.sqltext), "5")
def test_remove_computed_column(self):
m1 = MetaData()
m2 = MetaData()
Table(
"user",
m1,
Column("id", Integer, primary_key=True),
Column("foo", Integer, sa.Computed("5")),
)
Table("user", m2, Column("id", Integer, primary_key=True))
diffs = self._fixture(m1, m2)
eq_(diffs[0][0], "remove_column")
eq_(diffs[0][2], "user")
c = diffs[0][3]
eq_(c.name, "foo")
if config.requirements.computed_reflects_normally.enabled:
is_true(isinstance(c.computed, sa.Computed))
else:
is_(c.computed, None)
if config.requirements.computed_reflects_as_server_default.enabled:
is_true(isinstance(c.server_default, sa.DefaultClause))
eq_(str(c.server_default.arg.text), "5")
elif config.requirements.computed_reflects_normally.enabled:
is_true(isinstance(c.computed, sa.Computed))
else:
is_(c.computed, None)
@testing.combinations(
lambda: (None, sa.Computed("bar*5")),
(lambda: (sa.Computed("bar*5"), None)),
lambda: (
sa.Computed("bar*5"),
sa.Computed("bar * 42", persisted=True),
),
lambda: (sa.Computed("bar*5"), sa.Computed("bar * 42")),
)
@config.requirements.computed_reflects_normally
def test_cant_change_computed_warning(self, test_case):
arg_before, arg_after = testing.resolve_lambda(test_case, **locals())
m1 = MetaData()
m2 = MetaData()
arg_before = [] if arg_before is None else [arg_before]
arg_after = [] if arg_after is None else [arg_after]
Table(
"user",
m1,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer, *arg_before),
)
Table(
"user",
m2,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer, *arg_after),
)
with mock.patch("alembic.util.warn") as mock_warn:
diffs = self._fixture(m1, m2)
eq_(
mock_warn.mock_calls,
[mock.call("Computed default on user.foo cannot be modified")],
)
eq_(list(diffs), [])
@testing.combinations(
lambda: (None, None),
lambda: (sa.Computed("5"), sa.Computed("5")),
lambda: (sa.Computed("bar*5"), sa.Computed("bar*5")),
(
lambda: (sa.Computed("bar*5"), None),
config.requirements.computed_doesnt_reflect_as_server_default,
),
)
def test_computed_unchanged(self, test_case):
arg_before, arg_after = testing.resolve_lambda(test_case, **locals())
m1 = MetaData()
m2 = MetaData()
arg_before = [] if arg_before is None else [arg_before]
arg_after = [] if arg_after is None else [arg_after]
Table(
"user",
m1,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer, *arg_before),
)
Table(
"user",
m2,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer, *arg_after),
)
with mock.patch("alembic.util.warn") as mock_warn:
diffs = self._fixture(m1, m2)
eq_(mock_warn.mock_calls, [])
eq_(list(diffs), [])
@config.requirements.computed_reflects_as_server_default
def test_remove_computed_default_on_computed(self):
"""Asserts the current behavior which is that on PG and Oracle,
the GENERATED ALWAYS AS is reflected as a server default which we can't
tell is actually "computed", so these come out as a modification to
the server default.
"""
m1 = MetaData()
m2 = MetaData()
Table(
"user",
m1,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer, sa.Computed("bar + 42")),
)
Table(
"user",
m2,
Column("id", Integer, primary_key=True),
Column("bar", Integer),
Column("foo", Integer),
)
diffs = self._fixture(m1, m2)
eq_(diffs[0][0][0], "modify_default")
eq_(diffs[0][0][2], "user")
eq_(diffs[0][0][3], "foo")
old = diffs[0][0][-2]
new = diffs[0][0][-1]
is_(new, None)
is_true(isinstance(old, sa.DefaultClause))
if exclusions.against(config, "postgresql"):
eq_(str(old.arg.text), "(bar + 42)")
elif exclusions.against(config, "oracle"):
eq_(str(old.arg.text), '"BAR"+42')
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