Fixed #14028 - Added validation for clashing db_columns.

Thanks akaariai for the suggestion.

1 files changed, 53 insertions, 0 deletions

diff --git a/tests/invalid_models/invalid_models/models.py b/tests/invalid_models/invalid_models/models.py
index 66ce5c4c61..1113c0c056 100644
--- a/tests/invalid_models/invalid_models/models.py
+++ b/tests/invalid_models/invalid_models/models.py
@@ -364,6 +364,56 @@ class BadIndexTogether1(models.Model):
         ]
 
 
+class DuplicateColumnNameModel1(models.Model):
+    """
+    A field (bar) attempts to use a column name which is already auto-assigned
+    earlier in the class. This should raise a validation error.
+    """
+    foo = models.IntegerField()
+    bar = models.IntegerField(db_column='foo')
+
+    class Meta:
+        db_table = 'foobar'
+
+
+class DuplicateColumnNameModel2(models.Model):
+    """
+    A field (foo) attempts to use a column name which is already auto-assigned
+    later in the class. This should raise a validation error.
+    """
+    foo = models.IntegerField(db_column='bar')
+    bar = models.IntegerField()
+
+    class Meta:
+        db_table = 'foobar'
+
+
+class DuplicateColumnNameModel3(models.Model):
+    """Two fields attempt to use each others' names.
+
+    This is not a desirable scenario but valid nonetheless.
+
+    It should not raise a validation error.
+    """
+    foo = models.IntegerField(db_column='bar')
+    bar = models.IntegerField(db_column='foo')
+
+    class Meta:
+        db_table = 'foobar3'
+
+
+class DuplicateColumnNameModel4(models.Model):
+    """Two fields attempt to use the same db_column value.
+
+    This should raise a validation error.
+    """
+    foo = models.IntegerField(db_column='baz')
+    bar = models.IntegerField(db_column='baz')
+
+    class Meta:
+        db_table = 'foobar'
+
+
 model_errors = """invalid_models.fielderrors: "charfield": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield2": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield3": CharFields require a "max_length" attribute that is a positive integer.
@@ -477,6 +527,9 @@ invalid_models.hardreferencemodel: 'm2m_4' defines a relation with the model 'in
 invalid_models.badswappablevalue: TEST_SWAPPED_MODEL_BAD_VALUE is not of the form 'app_label.app_name'.
 invalid_models.badswappablemodel: Model has been swapped out for 'not_an_app.Target' which has not been installed or is abstract.
 invalid_models.badindextogether1: "index_together" refers to field_that_does_not_exist, a field that doesn't exist.
+invalid_models.duplicatecolumnnamemodel1: Field 'bar' has column name 'foo' that is already used.
+invalid_models.duplicatecolumnnamemodel2: Field 'bar' has column name 'bar' that is already used.
+invalid_models.duplicatecolumnnamemodel4: Field 'bar' has column name 'baz' that is already used.
 """
 
 if not connection.features.interprets_empty_strings_as_nulls: