Fixed #12460 -- Improved inspectdb handling of special field names

Thanks mihail lukin for the report and elijahr and kgibula for their
work on the patch.

2 files changed, 31 insertions, 12 deletions

diff --git a/tests/regressiontests/inspectdb/models.py b/tests/regressiontests/inspectdb/models.py
index 9f815855b6..352053aafe 100644
--- a/tests/regressiontests/inspectdb/models.py
+++ b/tests/regressiontests/inspectdb/models.py
@@ -19,3 +19,9 @@ class DigitsInColumnName(models.Model):
     all_digits = models.CharField(max_length=11, db_column='123')
     leading_digit = models.CharField(max_length=11, db_column='4extra')
     leading_digits = models.CharField(max_length=11, db_column='45extra')
+
+class UnderscoresInColumnName(models.Model):
+    field = models.IntegerField(db_column='field')
+    field_field_0 = models.IntegerField(db_column='Field_')
+    field_field_1 = models.IntegerField(db_column='Field__')
+    field_field_2 = models.IntegerField(db_column='__field')
diff --git a/tests/regressiontests/inspectdb/tests.py b/tests/regressiontests/inspectdb/tests.py
index aae7bc5cc7..b5647e9e38 100644
--- a/tests/regressiontests/inspectdb/tests.py
+++ b/tests/regressiontests/inspectdb/tests.py
@@ -1,3 +1,5 @@
+from __future__ import unicode_literals
+
 from django.core.management import call_command
 from django.test import TestCase, skipUnlessDBFeature
 from django.utils.six import StringIO
@@ -17,7 +19,6 @@ class InspectDBTestCase(TestCase):
         # the Django test suite, check that one of its tables hasn't been
         # inspected
         self.assertNotIn("class DjangoContentType(models.Model):", out.getvalue(), msg=error_message)
-        out.close()
 
     @skipUnlessDBFeature('can_introspect_foreign_keys')
     def test_attribute_name_not_python_keyword(self):
@@ -27,15 +28,16 @@ class InspectDBTestCase(TestCase):
         call_command('inspectdb',
                      table_name_filter=lambda tn:tn.startswith('inspectdb_'),
                      stdout=out)
+        output = out.getvalue()
         error_message = "inspectdb generated an attribute name which is a python keyword"
-        self.assertNotIn("from = models.ForeignKey(InspectdbPeople)", out.getvalue(), msg=error_message)
+        self.assertNotIn("from = models.ForeignKey(InspectdbPeople)", output, msg=error_message)
         # As InspectdbPeople model is defined after InspectdbMessage, it should be quoted
-        self.assertIn("from_field = models.ForeignKey('InspectdbPeople')", out.getvalue())
+        self.assertIn("from_field = models.ForeignKey('InspectdbPeople', db_column='from_id')",
+            output)
         self.assertIn("people_pk = models.ForeignKey(InspectdbPeople, primary_key=True)",
-            out.getvalue())
+            output)
         self.assertIn("people_unique = models.ForeignKey(InspectdbPeople, unique=True)",
-            out.getvalue())
-        out.close()
+            output)
 
     def test_digits_column_name_introspection(self):
         """Introspection of column names consist/start with digits (#16536/#17676)"""
@@ -45,13 +47,24 @@ class InspectDBTestCase(TestCase):
         call_command('inspectdb',
                      table_name_filter=lambda tn:tn.startswith('inspectdb_'),
                      stdout=out)
+        output = out.getvalue()
         error_message = "inspectdb generated a model field name which is a number"
-        self.assertNotIn("    123 = models.CharField", out.getvalue(), msg=error_message)
-        self.assertIn("number_123 = models.CharField", out.getvalue())
+        self.assertNotIn("    123 = models.CharField", output, msg=error_message)
+        self.assertIn("number_123 = models.CharField", output)
 
         error_message = "inspectdb generated a model field name which starts with a digit"
-        self.assertNotIn("    4extra = models.CharField", out.getvalue(), msg=error_message)
-        self.assertIn("number_4extra = models.CharField", out.getvalue())
+        self.assertNotIn("    4extra = models.CharField", output, msg=error_message)
+        self.assertIn("number_4extra = models.CharField", output)
+
+        self.assertNotIn("    45extra = models.CharField", output, msg=error_message)
+        self.assertIn("number_45extra = models.CharField", output)
 
-        self.assertNotIn("    45extra = models.CharField", out.getvalue(), msg=error_message)
-        self.assertIn("number_45extra = models.CharField", out.getvalue())
+    def test_underscores_column_name_introspection(self):
+        """Introspection of column names containing underscores (#12460)"""
+        out = StringIO()
+        call_command('inspectdb', stdout=out)
+        output = out.getvalue()
+        self.assertIn("field = models.IntegerField()", output)
+        self.assertIn("field_field = models.IntegerField(db_column='Field_')", output)
+        self.assertIn("field_field_0 = models.IntegerField(db_column='Field__')", output)
+        self.assertIn("field_field_1 = models.IntegerField(db_column='__field')", output)