gh-90016: Deprecate default sqlite3 adapters and converters

Doc/library/sqlite3.rst

@@ -1305,6 +1305,8 @@ This function can then be registered using :func:`register_adapter`.
 .. literalinclude:: ../includes/sqlite3/adapter_point_2.py
 
 
+.. _sqlite3-converters:
+
 Converting SQLite values to custom Python types
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -1345,27 +1347,23 @@ The following example illustrates the implicit and explicit approaches:
 .. literalinclude:: ../includes/sqlite3/converter_point.py
 
 
-Default adapters and converters
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-There are default adapters for the date and datetime types in the datetime
-module. They will be sent as ISO dates/ISO timestamps to SQLite.
+Default adapters and converters (deprecated)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-The default converters are registered under the name "date" for
-:class:`datetime.date` and under the name "timestamp" for
-:class:`datetime.datetime`.
-
-This way, you can use date/timestamps from Python without any additional
-fiddling in most cases. The format of the adapters is also compatible with the
-experimental SQLite date/time functions.
+.. note::
 
-The following example demonstrates this.
+   The default adapters and converters are deprecated as of Python 3.12.
+   Instead, use the :ref:`sqlite3-adapter-converter-recipes`,
+   and tailor them to your needs.
 
-.. literalinclude:: ../includes/sqlite3/pysqlite_datetime.py
+The deprecated default adapters and converters consists of:
 
-If a timestamp stored in SQLite has a fractional part longer than 6
-numbers, its value will be truncated to microsecond precision by the
-timestamp converter.
+* Adapt :class:`datetime.date` objects to :class:`strings <str>` in ISO format.
+* Adapt :class:`datetime.datetime` objects to strings ISO format.
+* Convert :ref:`declared <sqlite3-converters>` "date" types to ``datetime.date``
+  objects.
+* Convert declared "timestamp" types to ``datetime.datetime`` objects.
+  Fractional parts will be truncated to 6 digits (microsecond precision).
 
 .. note::
 
@@ -1374,6 +1372,12 @@ timestamp converter.
    offsets in timestamps, either leave converters disabled, or register an
    offset-aware converter with :func:`register_converter`.
 
+.. versionchanged:: 3.12
+
+   Deprecated default adapters and converters.
+
+.. deprecated:: 3.12
+
 
 .. _sqlite3-adapter-converter-recipes:
 

Doc/whatsnew/3.12.rst

@@ -118,6 +118,9 @@ CPython bytecode changes
 Deprecated
 ==========
 
+* The default :mod:`sqlite3` adapters and converters are now deprecated.
+  (Contributed by Erlend E. Aasland in :gh:`90016`.)
+
 
 Pending Removal in Python 3.13
 ==============================

Lib/sqlite3/dbapi2.py

@@ -55,16 +55,24 @@ def TimestampFromTicks(ticks):
 collections.abc.Sequence.register(Row)
 
 def register_adapters_and_converters():
+    from warnings import warn
+
+    msg = "The default {what} are deprecated as of Python 3.12"
+
     def adapt_date(val):
+        warn(msg.format(what="adapters"), DeprecationWarning, stacklevel=2)
         return val.isoformat()
 
     def adapt_datetime(val):
+        warn(msg.format(what="adapters"), DeprecationWarning, stacklevel=2)
         return val.isoformat(" ")
 
     def convert_date(val):
+        warn(msg.format(what="converters"), DeprecationWarning, stacklevel=2)
         return datetime.date(*map(int, val.split(b"-")))
 
     def convert_timestamp(val):
+        warn(msg.format(what="converters"), DeprecationWarning, stacklevel=2)
         datepart, timepart = val.split(b" ")
         year, month, day = map(int, datepart.split(b"-"))
         timepart_full = timepart.split(b".")

Lib/test/test_sqlite3/test_regression.py

@@ -129,7 +129,8 @@ def test_type_map_usage(self):
         con = sqlite.connect(":memory:",detect_types=sqlite.PARSE_DECLTYPES)
         cur = con.cursor()
         cur.execute("create table foo(bar timestamp)")
-        cur.execute("insert into foo(bar) values (?)", (datetime.datetime.now(),))
+        with self.assertWarnsRegex(DeprecationWarning, "adapters"):
+            cur.execute("insert into foo(bar) values (?)", (datetime.datetime.now(),))
         cur.execute(SELECT)
         cur.execute("drop table foo")
         cur.execute("create table foo(bar integer)")
@@ -305,7 +306,8 @@ def test_convert_timestamp_microsecond_padding(self):
         cur.execute("INSERT INTO t (x) VALUES ('2012-04-04 15:06:00.123456789')")
 
         cur.execute("SELECT * FROM t")
-        values = [x[0] for x in cur.fetchall()]
+        with self.assertWarnsRegex(DeprecationWarning, "converters"):
+            values = [x[0] for x in cur.fetchall()]
 
         self.assertEqual(values, [
             datetime.datetime(2012, 4, 4, 15, 6, 0, 456000),

Lib/test/test_sqlite3/test_types.py

@@ -496,38 +496,51 @@ def tearDown(self):
 
     def test_sqlite_date(self):
         d = sqlite.Date(2004, 2, 14)
-        self.cur.execute("insert into test(d) values (?)", (d,))
+        with self.assertWarnsRegex(DeprecationWarning, "adapters") as cm:
+            self.cur.execute("insert into test(d) values (?)", (d,))
+        self.assertEqual(cm.filename, __file__)
         self.cur.execute("select d from test")
-        d2 = self.cur.fetchone()[0]
+        with self.assertWarnsRegex(DeprecationWarning, "converters") as cm:
+            d2 = self.cur.fetchone()[0]
+        self.assertEqual(cm.filename, __file__)
         self.assertEqual(d, d2)
 
     def test_sqlite_timestamp(self):
         ts = sqlite.Timestamp(2004, 2, 14, 7, 15, 0)
-        self.cur.execute("insert into test(ts) values (?)", (ts,))
+        with self.assertWarnsRegex(DeprecationWarning, "adapters") as cm:
+            self.cur.execute("insert into test(ts) values (?)", (ts,))
+        self.assertEqual(cm.filename, __file__)
         self.cur.execute("select ts from test")
-        ts2 = self.cur.fetchone()[0]
+        with self.assertWarnsRegex(DeprecationWarning, "converters") as cm:
+            ts2 = self.cur.fetchone()[0]
+        self.assertEqual(cm.filename, __file__)
         self.assertEqual(ts, ts2)
 
     def test_sql_timestamp(self):
         now = datetime.datetime.utcnow()
         self.cur.execute("insert into test(ts) values (current_timestamp)")
         self.cur.execute("select ts from test")
-        ts = self.cur.fetchone()[0]
+        with self.assertWarnsRegex(DeprecationWarning, "converters"):
+            ts = self.cur.fetchone()[0]
         self.assertEqual(type(ts), datetime.datetime)
         self.assertEqual(ts.year, now.year)
 
     def test_date_time_sub_seconds(self):
         ts = sqlite.Timestamp(2004, 2, 14, 7, 15, 0, 500000)
-        self.cur.execute("insert into test(ts) values (?)", (ts,))
+        with self.assertWarnsRegex(DeprecationWarning, "adapters"):
+            self.cur.execute("insert into test(ts) values (?)", (ts,))
         self.cur.execute("select ts from test")
-        ts2 = self.cur.fetchone()[0]
+        with self.assertWarnsRegex(DeprecationWarning, "converters"):
+            ts2 = self.cur.fetchone()[0]
         self.assertEqual(ts, ts2)
 
     def test_date_time_sub_seconds_floating_point(self):
         ts = sqlite.Timestamp(2004, 2, 14, 7, 15, 0, 510241)
-        self.cur.execute("insert into test(ts) values (?)", (ts,))
+        with self.assertWarnsRegex(DeprecationWarning, "adapters"):
+            self.cur.execute("insert into test(ts) values (?)", (ts,))
         self.cur.execute("select ts from test")
-        ts2 = self.cur.fetchone()[0]
+        with self.assertWarnsRegex(DeprecationWarning, "converters"):
+            ts2 = self.cur.fetchone()[0]
         self.assertEqual(ts, ts2)
 
 

Misc/NEWS.d/next/Library/2022-06-25-23-44-44.gh-issue-90016.EB409s.rst

@@ -0,0 +1,2 @@
+Deprecate default :mod:`sqlite3` adapters and converters. Patch by Erlend E.
+Aasland.