[1.8.x] Fixed #25274 --- Made inspectdb handle renamed fields in unique_together.

Backport of 2cb50f935a from master

django/core/management/commands/inspectdb.py

@@ -73,6 +73,7 @@ class Command(BaseCommand):
                 except NotImplementedError:
                     constraints = {}
                 used_column_names = []  # Holds column names used in the table so far
+                column_to_field_name = {}  # Maps column names to names of model fields
                 for row in connection.introspection.get_table_description(cursor, table_name):
                     comment_notes = []  # Holds Field notes, to be displayed in a Python comment.
                     extra_params = OrderedDict()  # Holds Field parameters such as 'db_column'.
@@ -85,6 +86,7 @@ class Command(BaseCommand):
                     comment_notes.extend(notes)
 
                     used_column_names.append(att_name)
+                    column_to_field_name[column_name] = att_name
 
                     # Add primary_key and unique, if necessary.
                     if column_name in indexes:
@@ -141,7 +143,7 @@ class Command(BaseCommand):
                     if comment_notes:
                         field_desc += '  # ' + ' '.join(comment_notes)
                     yield '    %s' % field_desc
-                for meta_line in self.get_meta(table_name, constraints):
+                for meta_line in self.get_meta(table_name, constraints, column_to_field_name):
                     yield meta_line
 
     def normalize_col_name(self, col_name, used_column_names, is_relation):
@@ -238,7 +240,7 @@ class Command(BaseCommand):
 
         return field_type, field_params, field_notes
 
-    def get_meta(self, table_name, constraints):
+    def get_meta(self, table_name, constraints, column_to_field_name):
         """
         Return a sequence comprising the lines of code necessary
         to construct the inner Meta class for the model corresponding
@@ -251,7 +253,7 @@ class Command(BaseCommand):
                 if len(columns) > 1:
                     # we do not want to include the u"" or u'' prefix
                     # so we build the string rather than interpolate the tuple
-                    tup = '(' + ', '.join("'%s'" % c for c in columns) + ')'
+                    tup = '(' + ', '.join("'%s'" % column_to_field_name[c] for c in columns) + ')'
                     unique_together.append(tup)
         meta = ["",
                 "    class Meta:",

docs/releases/1.8.8.txt

@@ -9,4 +9,5 @@ Django 1.8.8 fixes several bugs in 1.8.7.
 Bugfixes
 ========
 
-* ...
+* Fixed incorrect ``unique_together`` field name generation by ``inspectdb``
+  (:ticket:`25274`).

tests/inspectdb/models.py

@@ -73,6 +73,13 @@ class ColumnTypes(models.Model):
 class UniqueTogether(models.Model):
     field1 = models.IntegerField()
     field2 = models.CharField(max_length=10)
+    from_field = models.IntegerField(db_column='from')
+    non_unique = models.IntegerField(db_column='non__unique_column')
+    non_unique_0 = models.IntegerField(db_column='non_unique__column')
 
     class Meta:
-        unique_together = ('field1', 'field2')
+        unique_together = [
+            ('field1', 'field2'),
+            ('from_field', 'field1'),
+            ('non_unique', 'non_unique_0'),
+        ]

tests/inspectdb/tests.py

@@ -226,7 +226,18 @@ class InspectDBTestCase(TestCase):
                      table_name_filter=lambda tn: tn.startswith('inspectdb_uniquetogether'),
                      stdout=out)
         output = out.getvalue()
-        self.assertIn("        unique_together = (('field1', 'field2'),)", output, msg='inspectdb should generate unique_together.')
+        unique_re = re.compile(r'.*unique_together = \((.+),\).*')
+        unique_together_match = re.findall(unique_re, output)
+        # There should be one unique_together tuple.
+        self.assertEqual(len(unique_together_match), 1)
+        fields = unique_together_match[0]
+        # Fields with db_column = field name.
+        self.assertIn("('field1', 'field2')", fields)
+        # Fields from columns whose names are Python keywords.
+        self.assertIn("('field1', 'field2')", fields)
+        # Fields whose names normalize to the same Python field name and hence
+        # are given an integer suffix.
+        self.assertIn("('non_unique_column', 'non_unique_column_0')", fields)
 
     @skipUnless(connection.vendor == 'sqlite',
                 "Only patched sqlite's DatabaseIntrospection.data_types_reverse for this test")