]> git.ipfire.org Git - thirdparty/sqlalchemy/sqlalchemy.git/commitdiff
implement second-level type resolution for literals
authorMike Bayer <mike_mp@zzzcomputing.com>
Wed, 5 Jan 2022 17:20:46 +0000 (12:20 -0500)
committerMike Bayer <mike_mp@zzzcomputing.com>
Tue, 11 Jan 2022 14:24:34 +0000 (09:24 -0500)
Added additional rule to the system that determines ``TypeEngine``
implementations from Python literals to apply a second level of adjustment
to the type, so that a Python datetime with or without tzinfo can set the
``timezone=True`` parameter on the returned :class:`.DateTime` object, as
well as :class:`.Time`. This helps with some round-trip scenarios on
type-sensitive PostgreSQL dialects such as asyncpg, psycopg3 (2.0 only).

For 1.4 specifically, the backport improves support for asyncpg handling of
TIME WITH TIMEZONE, which was not fully implemented. 2.0's reworked
PostgreSQL architecture had this handled already.

Fixes: #7537
Change-Id: Icdb07db85af5f7f39f1c1ef855fe27609770094b

doc/build/changelog/unreleased_14/7537.rst [new file with mode: 0644]
lib/sqlalchemy/sql/sqltypes.py
lib/sqlalchemy/sql/type_api.py
lib/sqlalchemy/testing/requirements.py
lib/sqlalchemy/testing/suite/test_types.py
test/requirements.py

diff --git a/doc/build/changelog/unreleased_14/7537.rst b/doc/build/changelog/unreleased_14/7537.rst
new file mode 100644 (file)
index 0000000..d48cf30
--- /dev/null
@@ -0,0 +1,17 @@
+.. change::
+    :tags: bug, sql, postgresql
+    :tickets: 7537
+
+    Added additional rule to the system that determines ``TypeEngine``
+    implementations from Python literals to apply a second level of adjustment
+    to the type, so that a Python datetime with or without tzinfo can set the
+    ``timezone=True`` parameter on the returned :class:`.DateTime` object, as
+    well as :class:`.Time`. This helps with some round-trip scenarios on
+    type-sensitive PostgreSQL dialects such as asyncpg, psycopg3 (2.0 only).
+
+.. change::
+    :tags: bug, postgresql, asyncpg
+    :tickets: 7537
+
+    Improved support for asyncpg handling of TIME WITH TIMEZONE, which
+    was not fully implemented.
index cda7b35cda052e8ded24298f99f4c87ab74f51b1..8a862d121a1a2d35135d5d9052ceb63d96ad9be2 100644 (file)
@@ -622,6 +622,13 @@ class DateTime(_LookupExpressionAdapter, TypeEngine):
     def get_dbapi_type(self, dbapi):
         return dbapi.DATETIME
 
+    def _resolve_for_literal(self, value):
+        with_timezone = value.tzinfo is not None
+        if with_timezone and not self.timezone:
+            return DATETIME_TIMEZONE
+        else:
+            return self
+
     @property
     def python_type(self):
         return dt.datetime
@@ -692,6 +699,13 @@ class Time(_LookupExpressionAdapter, TypeEngine):
     def python_type(self):
         return dt.time
 
+    def _resolve_for_literal(self, value):
+        with_timezone = value.tzinfo is not None
+        if with_timezone and not self.timezone:
+            return TIME_TIMEZONE
+        else:
+            return self
+
     @util.memoized_property
     def _expression_adaptations(self):
         # Based on https://www.postgresql.org/docs/current/\
@@ -2994,6 +3008,8 @@ STRINGTYPE = String()
 INTEGERTYPE = Integer()
 MATCHTYPE = MatchType()
 TABLEVALUE = TableValueType()
+DATETIME_TIMEZONE = DateTime(timezone=True)
+TIME_TIMEZONE = Time(timezone=True)
 
 _type_map = {
     int: Integer(),
@@ -3031,7 +3047,7 @@ def _resolve_value_to_type(value):
             )
         return NULLTYPE
     else:
-        return _result_type
+        return _result_type._resolve_for_literal(value)
 
 
 # back-assign to type_api
index 07cd4d95fb3687570b62cccfcd99ed493894c5fe..b087dd1e94a5087e16d9bc2a163175dfd20219ce 100644 (file)
@@ -592,6 +592,17 @@ class TypeEngine(Traversible):
         )
         return new_type
 
+    def _resolve_for_literal(self, value):
+        """adjust this type given a literal Python value that will be
+        stored in a bound parameter.
+
+        Used exclusively by _resolve_value_to_type().
+
+        .. versionadded:: 1.4.30 or 2.0
+
+        """
+        return self
+
     @util.memoized_property
     def _type_affinity(self):
         """Return a rudimental 'affinity' value expressing the general class
index 5cf80a1fb8c9683fe0eb36b100319e599dd05c66..e87ed6edc698bff792ad3fa3a074911a30198e41 100644 (file)
@@ -753,6 +753,29 @@ class SuiteRequirements(Requirements):
 
         return exclusions.open()
 
+    @property
+    def datetime_timezone(self):
+        """target dialect supports representation of Python
+        datetime.datetime() with tzinfo with DateTime(timezone=True)."""
+
+        return exclusions.closed()
+
+    @property
+    def time_timezone(self):
+        """target dialect supports representation of Python
+        datetime.time() with tzinfo with Time(timezone=True)."""
+
+        return exclusions.closed()
+
+    @property
+    def datetime_implicit_bound(self):
+        """target dialect when given a datetime object will bind it such
+        that the database server knows the object is a datetime, and not
+        a plain string.
+
+        """
+        return exclusions.open()
+
     @property
     def datetime_microseconds(self):
         """target dialect supports representation of Python
@@ -767,6 +790,16 @@ class SuiteRequirements(Requirements):
         if TIMESTAMP is used."""
         return exclusions.closed()
 
+    @property
+    def timestamp_microseconds_implicit_bound(self):
+        """target dialect when given a datetime object which also includes
+        a microseconds portion when using the TIMESTAMP data type
+        will bind it such that the database server knows
+        the object is a datetime with microseconds, and not a plain string.
+
+        """
+        return self.timestamp_microseconds
+
     @property
     def datetime_historic(self):
         """target dialect supports representation of Python
index 78596457ee5a17d9c04ae3687656520c24924e7a..796de5d939f79ed47d728bea722c50191f487d27 100644 (file)
@@ -302,6 +302,11 @@ class _DateFixture(_LiteralRoundTripFixture, fixtures.TestBase):
             Column("decorated_date_data", Decorated),
         )
 
+    @testing.requires.datetime_implicit_bound
+    def test_select_direct(self, connection):
+        result = connection.scalar(select(literal(self.data)))
+        eq_(result, self.data)
+
     def test_round_trip(self, connection):
         date_table = self.tables.date_table
 
@@ -376,6 +381,15 @@ class DateTimeTest(_DateFixture, fixtures.TablesTest):
     data = datetime.datetime(2012, 10, 15, 12, 57, 18)
 
 
+class DateTimeTZTest(_DateFixture, fixtures.TablesTest):
+    __requires__ = ("datetime_timezone",)
+    __backend__ = True
+    datatype = DateTime(timezone=True)
+    data = datetime.datetime(
+        2012, 10, 15, 12, 57, 18, tzinfo=datetime.timezone.utc
+    )
+
+
 class DateTimeMicrosecondsTest(_DateFixture, fixtures.TablesTest):
     __requires__ = ("datetime_microseconds",)
     __backend__ = True
@@ -389,6 +403,11 @@ class TimestampMicrosecondsTest(_DateFixture, fixtures.TablesTest):
     datatype = TIMESTAMP
     data = datetime.datetime(2012, 10, 15, 12, 57, 18, 396)
 
+    @testing.requires.timestamp_microseconds_implicit_bound
+    def test_select_direct(self, connection):
+        result = connection.scalar(select(literal(self.data)))
+        eq_(result, self.data)
+
 
 class TimeTest(_DateFixture, fixtures.TablesTest):
     __requires__ = ("time",)
@@ -397,6 +416,13 @@ class TimeTest(_DateFixture, fixtures.TablesTest):
     data = datetime.time(12, 57, 18)
 
 
+class TimeTZTest(_DateFixture, fixtures.TablesTest):
+    __requires__ = ("time_timezone",)
+    __backend__ = True
+    datatype = Time(timezone=True)
+    data = datetime.time(12, 57, 18, tzinfo=datetime.timezone.utc)
+
+
 class TimeMicrosecondsTest(_DateFixture, fixtures.TablesTest):
     __requires__ = ("time_microseconds",)
     __backend__ = True
@@ -1515,6 +1541,7 @@ __all__ = (
     "JSONLegacyStringCastIndexTest",
     "DateTest",
     "DateTimeTest",
+    "DateTimeTZTest",
     "TextTest",
     "NumericTest",
     "IntegerTest",
@@ -1524,6 +1551,7 @@ __all__ = (
     "TimeMicrosecondsTest",
     "TimestampMicrosecondsTest",
     "TimeTest",
+    "TimeTZTest",
     "TrueDivTest",
     "DateTimeMicrosecondsTest",
     "DateHistoricTest",
index 3934dd23fc596e6edd55f005f942b38eac7a7b5e..eede69eb63e92a45c407ed7c5a2024d81fdd8704 100644 (file)
@@ -1046,6 +1046,23 @@ class DefaultRequirements(SuiteRequirements):
 
         return exclusions.open()
 
+    @property
+    def datetime_implicit_bound(self):
+        """target dialect when given a datetime object will bind it such
+        that the database server knows the object is a datetime, and not
+        a plain string.
+
+        """
+        return exclusions.fails_on(["mysql", "mariadb"])
+
+    @property
+    def datetime_timezone(self):
+        return exclusions.only_on("postgresql")
+
+    @property
+    def time_timezone(self):
+        return exclusions.only_on("postgresql") + exclusions.skip_if("+pg8000")
+
     @property
     def datetime_microseconds(self):
         """target dialect supports representation of Python
@@ -1061,6 +1078,10 @@ class DefaultRequirements(SuiteRequirements):
 
         return only_on(["oracle"])
 
+    @property
+    def timestamp_microseconds_implicit_bound(self):
+        return self.timestamp_microseconds + exclusions.fails_on(["oracle"])
+
     @property
     def datetime_historic(self):
         """target dialect supports representation of Python