Files
sqlalchemy/test/sql/test_case_statement.py
T
Mike Bayer 01c50c64e3 Remove all remaining removed_in_20 warnings slated for removal
Finalize all remaining removed-in-2.0 changes so that we
can begin doing pep-484 typing without old things
getting in the way (we will also have to do public_factory).

note there are a few "moved_in_20()" and "became_legacy_in_20()"
warnings still in place.  The SQLALCHEMY_WARN_20 variable
is now removed.

Also removed here are the legacy "in place mutators" for Select
statements, and some keyword-only argument signatures in Core
have been added.

Also in the big change department, the ORM mapper() function
is removed entirely; the Mapper class is otherwise unchanged,
just the public-facing API function.  Mappers are now always
given a registry in which to participate, however the
argument signature of Mapper is not changed. ideally "registry"
would be the first positional argument.

Fixes: #7257

Change-Id: Ic70c57b9f1cf7eb996338af5183b11bdeb3e1623
2022-01-05 19:28:49 -05:00

298 lines
8.8 KiB
Python

from sqlalchemy import and_
from sqlalchemy import case
from sqlalchemy import cast
from sqlalchemy import Column
from sqlalchemy import func
from sqlalchemy import Integer
from sqlalchemy import literal_column
from sqlalchemy import MetaData
from sqlalchemy import select
from sqlalchemy import String
from sqlalchemy import Table
from sqlalchemy import testing
from sqlalchemy import text
from sqlalchemy.sql import column
from sqlalchemy.sql import table
from sqlalchemy.testing import AssertsCompiledSQL
from sqlalchemy.testing import eq_
from sqlalchemy.testing import fixtures
info_table = None
class CaseTest(fixtures.TestBase, AssertsCompiledSQL):
__dialect__ = "default"
@classmethod
def setup_test_class(cls):
metadata = MetaData()
global info_table
info_table = Table(
"infos",
metadata,
Column("pk", Integer, primary_key=True),
Column("info", String(30)),
)
with testing.db.begin() as conn:
info_table.create(conn)
conn.execute(
info_table.insert(),
[
{"pk": 1, "info": "pk_1_data"},
{"pk": 2, "info": "pk_2_data"},
{"pk": 3, "info": "pk_3_data"},
{"pk": 4, "info": "pk_4_data"},
{"pk": 5, "info": "pk_5_data"},
{"pk": 6, "info": "pk_6_data"},
],
)
@classmethod
def teardown_test_class(cls):
with testing.db.begin() as conn:
info_table.drop(conn)
@testing.requires.subqueries
def test_case(self, connection):
inner = select(
case(
(info_table.c.pk < 3, "lessthan3"),
(and_(info_table.c.pk >= 3, info_table.c.pk < 7), "gt3"),
).label("x"),
info_table.c.pk,
info_table.c.info,
).select_from(info_table)
inner_result = connection.execute(inner).all()
# Outputs:
# lessthan3 1 pk_1_data
# lessthan3 2 pk_2_data
# gt3 3 pk_3_data
# gt3 4 pk_4_data
# gt3 5 pk_5_data
# gt3 6 pk_6_data
eq_(
inner_result,
[
("lessthan3", 1, "pk_1_data"),
("lessthan3", 2, "pk_2_data"),
("gt3", 3, "pk_3_data"),
("gt3", 4, "pk_4_data"),
("gt3", 5, "pk_5_data"),
("gt3", 6, "pk_6_data"),
],
)
outer = select(inner.alias("q_inner"))
outer_result = connection.execute(outer).all()
assert outer_result == [
("lessthan3", 1, "pk_1_data"),
("lessthan3", 2, "pk_2_data"),
("gt3", 3, "pk_3_data"),
("gt3", 4, "pk_4_data"),
("gt3", 5, "pk_5_data"),
("gt3", 6, "pk_6_data"),
]
w_else = select(
case(
[info_table.c.pk < 3, cast(3, Integer)],
[and_(info_table.c.pk >= 3, info_table.c.pk < 6), 6],
else_=0,
).label("x"),
info_table.c.pk,
info_table.c.info,
).select_from(info_table)
else_result = connection.execute(w_else).all()
eq_(
else_result,
[
(3, 1, "pk_1_data"),
(3, 2, "pk_2_data"),
(6, 3, "pk_3_data"),
(6, 4, "pk_4_data"),
(6, 5, "pk_5_data"),
(0, 6, "pk_6_data"),
],
)
def test_literal_interpretation_one(self):
"""note this is modified as of #7287 to accept strings, tuples
and other literal values as input
where they are interpreted as bound values just like any other
expression.
Previously, an exception would be raised that the literal was
ambiguous.
"""
self.assert_compile(
case(("x", "y")),
"CASE WHEN :param_1 THEN :param_2 END",
checkparams={"param_1": "x", "param_2": "y"},
)
def test_literal_interpretation_two(self):
"""note this is modified as of #7287 to accept strings, tuples
and other literal values as input
where they are interpreted as bound values just like any other
expression.
Previously, an exception would be raised that the literal was
ambiguous.
"""
self.assert_compile(
case(
(("x", "y"), "z"),
),
"CASE WHEN :param_1 THEN :param_2 END",
checkparams={"param_1": ("x", "y"), "param_2": "z"},
)
def test_literal_interpretation_two_point_five(self):
"""note this is modified as of #7287 to accept strings, tuples
and other literal values as input
where they are interpreted as bound values just like any other
expression.
Previously, an exception would be raised that the literal was
ambiguous.
"""
self.assert_compile(
case(
(12, "z"),
),
"CASE WHEN :param_1 THEN :param_2 END",
checkparams={"param_1": 12, "param_2": "z"},
)
def test_literal_interpretation_three(self):
t = table("test", column("col1"))
self.assert_compile(
case(("x", "y"), value=t.c.col1),
"CASE test.col1 WHEN :param_1 THEN :param_2 END",
)
self.assert_compile(
case((t.c.col1 == 7, "y"), else_="z"),
"CASE WHEN (test.col1 = :col1_1) THEN :param_1 ELSE :param_2 END",
)
@testing.combinations(
(
(lambda t: ({"x": "y"}, t.c.col1, None)),
"CASE test.col1 WHEN :param_1 THEN :param_2 END",
),
(
(lambda t: ({"x": "y", "p": "q"}, t.c.col1, None)),
"CASE test.col1 WHEN :param_1 THEN :param_2 "
"WHEN :param_3 THEN :param_4 END",
),
(
(lambda t: ({t.c.col1 == 7: "x"}, None, 10)),
"CASE WHEN (test.col1 = :col1_1) THEN :param_1 ELSE :param_2 END",
),
(
(lambda t: ({t.c.col1 == 7: "x", t.c.col1 == 10: "y"}, None, 10)),
"CASE WHEN (test.col1 = :col1_1) THEN :param_1 "
"WHEN (test.col1 = :col1_2) THEN :param_2 ELSE :param_3 END",
),
argnames="test_case, expected",
)
def test_when_dicts(self, test_case, expected):
t = table("test", column("col1"))
when_dict, value, else_ = testing.resolve_lambda(test_case, t=t)
self.assert_compile(
case(when_dict, value=value, else_=else_), expected
)
def test_text_doesnt_explode(self, connection):
for s in [
select(
case(
(info_table.c.info == "pk_4_data", text("'yes'")),
else_=text("'no'"),
)
).order_by(info_table.c.info),
select(
case(
(
info_table.c.info == "pk_4_data",
literal_column("'yes'"),
),
else_=literal_column("'no'"),
)
).order_by(info_table.c.info),
]:
eq_(
connection.execute(s).all(),
[("no",), ("no",), ("no",), ("yes",), ("no",), ("no",)],
)
def test_text_doenst_explode_even_in_whenlist(self):
"""test #7287"""
self.assert_compile(
case(
(text(":case = 'upper'"), func.upper(literal_column("q"))),
else_=func.lower(literal_column("q")),
),
"CASE WHEN :case = 'upper' THEN upper(q) ELSE lower(q) END",
)
def testcase_with_dict(self):
query = select(
case(
{
info_table.c.pk < 3: "lessthan3",
info_table.c.pk >= 3: "gt3",
},
else_="other",
),
info_table.c.pk,
info_table.c.info,
).select_from(info_table)
eq_(
query.execute().fetchall(),
[
("lessthan3", 1, "pk_1_data"),
("lessthan3", 2, "pk_2_data"),
("gt3", 3, "pk_3_data"),
("gt3", 4, "pk_4_data"),
("gt3", 5, "pk_5_data"),
("gt3", 6, "pk_6_data"),
],
)
simple_query = (
select(
case(
{1: "one", 2: "two"}, value=info_table.c.pk, else_="other"
),
info_table.c.pk,
)
.where(info_table.c.pk < 4)
.select_from(info_table)
)
assert simple_query.execute().fetchall() == [
("one", 1),
("two", 2),
("other", 3),
]