BUG25965922: Add support for Django 1.11

This patch fixes the following issues with Django 1.11:

- Added optional name parameter to create_cursor in base.py to
  allow for name variable being passed in base backend _cursor
  method.
- Added DatabaseWrapper class attributes to base.py required in
  Django 1.11 base backend.
- Added column default in DatabaseIntrospection.

Tests were modified for regression.

Author: nmariz

lib/mysql/connector/django/base.py

@@ -22,14 +22,14 @@
 import warnings
 
 import django
+from django.core.exceptions import ImproperlyConfigured
 from django.utils.functional import cached_property
 
 try:
     import mysql.connector
     from mysql.connector.conversion import MySQLConverter, MySQLConverterBase
     from mysql.connector.catch23 import PY2
 except ImportError as err:
-    from django.core.exceptions import ImproperlyConfigured
     raise ImproperlyConfigured(
         "Error loading mysql.connector module: {0}".format(err))
 
@@ -47,7 +47,6 @@
     HAVE_CEXT = True
 
 if version < (1, 1):
-    from django.core.exceptions import ImproperlyConfigured
     raise ImproperlyConfigured(
         "MySQL Connector/Python v1.1.0 or newer "
         "is required; you have %s" % mysql.connector.__version__)
@@ -332,6 +331,14 @@ def data_types(self):
     SchemaEditorClass = DatabaseSchemaEditor
     Database = mysql.connector
 
+    if django.VERSION >= (1, 11):
+        client_class = DatabaseClient
+        creation_class = DatabaseCreation
+        features_class = DatabaseFeatures
+        introspection_class = DatabaseIntrospection
+        ops_class = DatabaseOperations
+        validation_class = DatabaseValidation
+
     def __init__(self, *args, **kwargs):
         super(DatabaseWrapper, self).__init__(*args, **kwargs)
 
@@ -344,12 +351,13 @@ def __init__(self, *args, **kwargs):
             self.converter = DjangoCMySQLConverter()
         else:
             self.converter = DjangoMySQLConverter()
-        self.ops = DatabaseOperations(self)
-        self.features = DatabaseFeatures(self)
-        self.client = DatabaseClient(self)
-        self.creation = DatabaseCreation(self)
-        self.introspection = DatabaseIntrospection(self)
-        self.validation = DatabaseValidation(self)
+        if django.VERSION < (1, 11):
+            self.ops = DatabaseOperations(self)
+            self.features = DatabaseFeatures(self)
+            self.client = DatabaseClient(self)
+            self.creation = DatabaseCreation(self)
+            self.introspection = DatabaseIntrospection(self)
+            self.validation = DatabaseValidation(self)
 
     def _valid_connection(self):
         if self.connection:
@@ -418,7 +426,7 @@ def init_connection_state(self):
             except AttributeError:
                 self._set_autocommit(self.settings_dict['AUTOCOMMIT'])
 
-    def create_cursor(self):
+    def create_cursor(self, name=None):
         # Django 1.6
         cursor = self.connection.cursor()
         return CursorWrapper(cursor)

lib/mysql/connector/django/introspection.py

@@ -72,7 +72,53 @@ def get_table_list(self, cursor):
         else:
             return [row[0] for row in cursor.fetchall()]
 
-    if django.VERSION >= (1, 8):
+    if django.VERSION >= (1, 11):
+        def get_table_description(self, cursor, table_name):
+            """
+            Returns a description of the table, with the DB-API
+            cursor.description interface."
+            """
+            # - information_schema database gives more accurate results for
+            #   some figures:
+            # - varchar length returned by cursor.description is an internal
+            #   length, not visible length (#5725)
+            # - precision and scale (for decimal fields) (#5014)
+            # - auto_increment is not available in cursor.description
+
+            InfoLine = namedtuple('InfoLine', 'col_name data_type max_len '
+                                  'num_prec num_scale extra column_default')
+            cursor.execute("""
+                SELECT column_name, data_type, character_maximum_length,
+                numeric_precision, numeric_scale, extra, column_default
+                FROM information_schema.columns
+                WHERE table_name = %s AND table_schema = DATABASE()""",
+                           [table_name])
+            field_info = dict(
+                (line[0], InfoLine(*line)) for line in cursor.fetchall()
+            )
+
+            cursor.execute("SELECT * FROM %s LIMIT 1"
+                           % self.connection.ops.quote_name(table_name))
+            to_int = lambda i: int(i) if i is not None else i
+            fields = []
+            for line in cursor.description:
+                col_name = force_text(line[0])
+                fields.append(
+                    FieldInfo(*(
+                        (col_name,) +
+                        line[1:3] +
+                        (
+                            to_int(field_info[col_name].max_len) or line[3],
+                            to_int(field_info[col_name].num_prec) or line[4],
+                            to_int(field_info[col_name].num_scale) or line[5],
+                            line[6],
+                            field_info[col_name].column_default,
+                            field_info[col_name].extra,
+                        )
+                    ))
+                )
+            return fields
+    elif django.VERSION >= (1, 8):
         def get_table_description(self, cursor, table_name):
             """
             Returns a description of the table, with the DB-API

tests/test_django.py

@@ -148,8 +148,12 @@ def test_get_table_list(self):
             if sys.version_info < (2, 7):
                 self.assertTrue(exp in self.introspect.get_table_list(cur))
             else:
-                res = any(table.name == exp
-                          for table in self.introspect.get_table_list(cur))
+                if tests.DJANGO_VERSION < (1, 8):
+                    res = any(table == exp
+                              for table in self.introspect.get_table_list(cur))
+                else:
+                    res = any(table.name == exp
+                              for table in self.introspect.get_table_list(cur))
                 self.assertTrue(res, "Table {table_name} not in table list"
                                      "".format(table_name=exp))
 
@@ -174,7 +178,7 @@ def test_get_table_description(self):
                           internal_size=20, precision=None, scale=None,
                           null_ok=1)
             ]
-        else:
+        elif tests.DJANGO_VERSION < (1, 11):
             exp = [
                 FieldInfo(name=u'id', type_code=3, display_size=None,
                           internal_size=None, precision=10, scale=None,
@@ -186,6 +190,18 @@ def test_get_table_description(self):
                           internal_size=20, precision=None, scale=None,
                           null_ok=1, extra=u'')
             ]
+        else:
+            exp = [
+                FieldInfo(name=u'id', type_code=3, display_size=None,
+                          internal_size=None, precision=10, scale=None,
+                          null_ok=0, default=None, extra=u'auto_increment'),
+                FieldInfo(name=u'c1', type_code=3, display_size=None,
+                          internal_size=None, precision=10, scale=None,
+                          null_ok=1, default=None, extra=u''),
+                FieldInfo(name=u'c2', type_code=253, display_size=None,
+                          internal_size=20, precision=None, scale=None,
+                          null_ok=1, default=None, extra=u'')
+            ]
         res = self.introspect.get_table_description(cur, 'django_t1')
         self.assertEqual(exp, res)