Provide tests for mixed-case column names

[John Shaffer <jshaffer2112@…>]

Django generates this query, which gives this error:

SELECT setval('"product_item_relatedItems_id_seq"', (SELECT max("id") FROM product_item_relatedItems));

psycopg.ProgrammingError: ERROR:  relation "product_item_relateditems" does not exist

I'm attaching a patch to generate this query instead:

SELECT setval('"product_item_relatedItems_id_seq"', (SELECT max("id") FROM "product_item_relatedItems"));

[John Shaffer <jshaffer2112@…>]

I noticed that the psycopg2 backend has the same issue, so here is an additional patch.

[John Shaffer <jshaffer2112@…>]

Patch against [5678].

[John Shaffer <jshaffer2112@…>]

To reproduce:

• Create a model with a mixed-case ManyToManyField:

  class Item(models.Model):
      relatedItems = models.ManyToManyField('self', blank=True, null=True)
  

• Load a fixture:

  - fields:
      relatedItems: []
    model: product.item
    pk: '1'
  

• You'll get a backtrace here:

  psycopg2.ProgrammingError: relation "product_item_relateditems" does not exist
  

[John Shaffer <jshaffer2112@…>]

Patch against [5743], with tests.

[Simon G. <dev@…>]

#4557 sounds like a similar problem.

[John Shaffer <jshaffer2112@…>]

Patch against [5988].

[Michael Radziej]

John, can you bring this up on the developer mailing list? Everything looks good to me, but I don't have the expertise needed here, so I hesitate to put this into "ready for checkin".

I wouldn't mind anybody to advance the stage of this ticket if they think so.

[Michael Radziej]

reverting my accidental state change.

[Chris Beaven]

This has actually been fixed in [6507] in response to #5710, but it didn't have tests in that one. It would be good to get your test in John, so could you please provide an updated patch? Thanks

[John Shaffer]

Patch against [7583].

[Adam Nelson]

Patch needs to be updated again.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[velis]

I just want to clarify: it says tests are needed, but the appropriate checkbox is not ticked. So, is it the tests that are needed or is there something more to this ticket?
p.s.: I'm sprinting django on PyCon UK and I'm looking at this ticket because I have dealt with this problem before. So I know what the issue was, I can write the appropriate tests, but I also want to make it right so that my first contribution wouldn't end up a failure :)

[velis]

​https://github.com/django/django/pull/1667

Please review

I created a model for testing mixed case entity names + a suite of 4 tests that test that. Since PostgreSQL lowercases everything not in quotes, usually only the last test would fail if this isn't implemented properly in the drivers.
Tested the unit-tests on PostgreSQL 9.2 and SQLite

[Tim Graham]

On further investigation, I think we have tests to cover this. In particular, if I comment out the fix from [6507], I get a failure in test_generic_relation (backends.tests.SequenceResetTest), and here are some models with mixed case column names:

aggregation_regress/models.py:    Entry = models.CharField(unique=True, max_length=50)
aggregation_regress/models.py:    Clue = models.CharField(max_length=150)