#29049: Add slicing notation to F expressions
-------------------------------------+-------------------------------------
     Reporter:  Matthew Pava         |                    Owner:  Abhinav
                                     |  Yadav
         Type:  New feature          |                   Status:  assigned
    Component:  Database layer       |                  Version:  dev
  (models, ORM)                      |
     Severity:  Normal               |               Resolution:
     Keywords:  slice F              |             Triage Stage:  Accepted
    Has patch:  1                    |      Needs documentation:  0
  Needs tests:  0                    |  Patch needs improvement:  1
Easy pickings:  0                    |                    UI/UX:  0
-------------------------------------+-------------------------------------

Comment (by Abhinav Yadav):

 I have been reading up about this issue to continue and finish it off from
 where David left it, and I have some doubts. The SQL query left by Felix
 [https://github.com/django/django/pull/14731#discussion_r745505740 in this
 comment] also doesn't generate any QuerySet or objects. I tried to run
 that query using `Manager.raw()`, which generated no results.

 Further I investigated the `resolve_expression` method of `SliceableF`
 class in `django/db/models/expressions.py`, and compared it to other
 implementations of resovle_expression method in other classes but couldn't
 find anything concrete which might point to where the error might be.

 Does a special method for handling slicing and indexing for OuterRef query
 need to be written so it is properly resolved? That is what I'm thinking
 because I can't find anything else that is properly handling slicing for
 OuterRef Queries, unless I'm missing something.

 Also should `None` be used instead of `''` in slice_expression for end if
 length is not provided?

-- 
Ticket URL: <https://code.djangoproject.com/ticket/29049#comment:22>
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