Fixed #27649 -- Bumped required cx_Oracle to 5.2.

Removed obsolete workarounds from 1aa48898085ea16915877cc139e238a74e3f554b
and dcf3be7a621f011a918453527406216a738acf68.

django/db/backends/oracle/base.py

@@ -62,7 +62,7 @@ from .features import DatabaseFeatures                      # NOQA isort:skip
 from .introspection import DatabaseIntrospection            # NOQA isort:skip
 from .operations import DatabaseOperations                  # NOQA isort:skip
 from .schema import DatabaseSchemaEditor                    # NOQA isort:skip
-from .utils import Oracle_datetime, convert_unicode         # NOQA isort:skip
+from .utils import Oracle_datetime                          # NOQA isort:skip
 
 
 class _UninitializedOperatorsDescriptor(object):
@@ -208,8 +208,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         return conn_params
 
     def get_new_connection(self, conn_params):
-        conn_string = convert_unicode(self._connect_string())
-        return Database.connect(conn_string, **conn_params)
+        return Database.connect(self._connect_string(), **conn_params)
 
     def init_connection_state(self):
         cursor = self.create_cursor()
@@ -246,13 +245,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
                 self.operators = self._standard_operators
                 self.pattern_ops = self._standard_pattern_ops
             cursor.close()
-
-        try:
-            self.connection.stmtcachesize = 20
-        except AttributeError:
-            # Django docs specify cx_Oracle version 4.3.1 or higher, but
-            # stmtcachesize is available only in 4.3.2 and up.
-            pass
+        self.connection.stmtcachesize = 20
         # Ensure all changes are preserved even when AUTOCOMMIT is False.
         if not self.get_autocommit():
             self.commit()
@@ -265,7 +258,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
             try:
                 return self.connection.commit()
             except Database.DatabaseError as e:
-                # cx_Oracle 5.0.4 raises a cx_Oracle.DatabaseError exception
+                # cx_Oracle raises a cx_Oracle.DatabaseError exception
                 # with the following attributes and values:
                 #  code = 2091
                 #  message = 'ORA-02091: transaction rolled back
@@ -363,7 +356,7 @@ class OracleParam(object):
         else:
             # To transmit to the database, we need Unicode if supported
             # To get size right, we must consider bytes.
-            self.force_bytes = convert_unicode(param, cursor.charset, strings_only)
+            self.force_bytes = force_text(param, cursor.charset, strings_only)
             if isinstance(self.force_bytes, six.string_types):
                 # We could optimize by only converting up to 4000 bytes here
                 string_size = len(force_bytes(param, cursor.charset, strings_only))
@@ -459,11 +452,11 @@ class FormatStylePlaceholderCursor(object):
             query = query[:-1]
         if params is None:
             params = []
-            query = convert_unicode(query, self.charset)
+            query = query
         elif hasattr(params, 'keys'):
             # Handle params as dict
             args = {k: ":%s" % k for k in params.keys()}
-            query = convert_unicode(query % args, self.charset)
+            query = query % args
         elif unify_by_values and len(params) > 0:
             # Handle params as a dict with unified query parameters by their
             # values. It can be used only in single query execute() because
@@ -480,23 +473,17 @@ class FormatStylePlaceholderCursor(object):
             params_dict = {param: ':arg%d' % i for i, param in enumerate(set(params))}
             args = [params_dict[param] for param in params]
             params = dict(zip(params_dict.values(), list(zip(*params_dict.keys()))[0]))
-            query = convert_unicode(query % tuple(args), self.charset)
+            query = query % tuple(args)
         else:
             # Handle params as sequence
             args = [(':arg%d' % i) for i in range(len(params))]
-            query = convert_unicode(query % tuple(args), self.charset)
-        return query, self._format_params(params)
+            query = query % tuple(args)
+        return force_text(query, self.charset), self._format_params(params)
 
     def execute(self, query, params=None):
         query, params = self._fix_for_params(query, params, unify_by_values=True)
         self._guess_input_sizes([params])
-        try:
-            return self.cursor.execute(query, self._param_generator(params))
-        except Database.DatabaseError as e:
-            # cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400.
-            if hasattr(e.args[0], 'code') and e.args[0].code == 1400 and not isinstance(e, Database.IntegrityError):
-                six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
-            raise
+        return self.cursor.execute(query, self._param_generator(params))
 
     def executemany(self, query, params=None):
         if not params:
@@ -509,13 +496,7 @@ class FormatStylePlaceholderCursor(object):
         # more than once, we can't make it lazy by using a generator
         formatted = [firstparams] + [self._format_params(p) for p in params_iter]
         self._guess_input_sizes(formatted)
-        try:
-            return self.cursor.executemany(query, [self._param_generator(p) for p in formatted])
-        except Database.DatabaseError as e:
-            # cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400.
-            if hasattr(e.args[0], 'code') and e.args[0].code == 1400 and not isinstance(e, Database.IntegrityError):
-                six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
-            raise
+        return self.cursor.executemany(query, [self._param_generator(p) for p in formatted])
 
     def fetchone(self):
         row = self.cursor.fetchone()

django/db/backends/oracle/operations.py

@@ -11,7 +11,7 @@ from django.utils import six, timezone
 from django.utils.encoding import force_bytes, force_text
 
 from .base import Database
-from .utils import InsertIdVar, Oracle_datetime, convert_unicode
+from .utils import InsertIdVar, Oracle_datetime
 
 
 class DatabaseOperations(BaseDatabaseOperations):
@@ -310,10 +310,10 @@ WHEN (new.%(col_name)s IS NULL)
         return "RETURNING %s INTO %%s", (InsertIdVar(),)
 
     def savepoint_create_sql(self, sid):
-        return convert_unicode("SAVEPOINT " + self.quote_name(sid))
+        return "SAVEPOINT " + self.quote_name(sid)
 
     def savepoint_rollback_sql(self, sid):
-        return convert_unicode("ROLLBACK TO SAVEPOINT " + self.quote_name(sid))
+        return "ROLLBACK TO SAVEPOINT " + self.quote_name(sid)
 
     def sql_flush(self, style, tables, sequences, allow_cascade=False):
         # Return a list of 'TRUNCATE x;', 'TRUNCATE y;',

django/db/backends/oracle/utils.py

@@ -1,18 +1,7 @@
 import datetime
 
-from django.utils.encoding import force_bytes, force_text
-
 from .base import Database
 
-# Check whether cx_Oracle was compiled with the WITH_UNICODE option if cx_Oracle is pre-5.1. This will
-# also be True for cx_Oracle 5.1 and in Python 3.0. See #19606
-if int(Database.version.split('.', 1)[0]) >= 5 and \
-        (int(Database.version.split('.', 2)[1]) >= 1 or
-         not hasattr(Database, 'UNICODE')):
-    convert_unicode = force_text
-else:
-    convert_unicode = force_bytes
-
 
 class InsertIdVar(object):
     """

docs/ref/databases.txt

@@ -731,17 +731,7 @@ Oracle notes
 ============
 
 Django supports `Oracle Database Server`_ versions 11.2 and higher. Version
-4.3.1 or higher of the `cx_Oracle`_ Python driver is required, although we
-recommend version 5.1.3 or later as these versions support Python 3.
-
-Note that due to a Unicode-corruption bug in ``cx_Oracle`` 5.0, that
-version of the driver should **not** be used with Django;
-``cx_Oracle`` 5.0.1 resolved this issue, so if you'd like to use a
-more recent ``cx_Oracle``, use version 5.0.1.
-
-``cx_Oracle`` 5.0.1 or greater can optionally be compiled with the
-``WITH_UNICODE`` environment variable.  This is recommended but not
-required.
+5.2 or higher of the `cx_Oracle`_ Python driver is required.
 
 .. _`Oracle Database Server`: http://www.oracle.com/
 .. _`cx_Oracle`: http://cx-oracle.sourceforge.net/

docs/releases/1.11.txt

@@ -698,6 +698,8 @@ Miscellaneous
   leaves ``request.POST`` immutable. If you're modifying that ``QueryDict``,
   you must now first copy it, e.g. ``request.POST.copy()``.
 
+* Support for ``cx_Oracle`` < 5.2 is removed.
+
 .. _deprecated-features-1.11:
 
 Features deprecated in 1.11

tests/backends/tests.py

@@ -86,11 +86,8 @@ class OracleTests(unittest.TestCase):
     def test_dbms_session(self):
         # If the backend is Oracle, test that we can call a standard
         # stored procedure through our cursor wrapper.
-        from django.db.backends.oracle.base import convert_unicode
-
         with connection.cursor() as cursor:
-            cursor.callproc(convert_unicode('DBMS_SESSION.SET_IDENTIFIER'),
-                            [convert_unicode('_django_testing!')])
+            cursor.callproc('DBMS_SESSION.SET_IDENTIFIER', ['_django_testing!'])
 
     def test_cursor_var(self):
         # If the backend is Oracle, test that we can pass cursor variables