Wrong ordering by a field in a different table example in new (development ) queryset-api documentation

[Jerzy.Ludwichowski@…]

The example on ordering a queryset by a field in a different table in the development documentation on queryset-api (​http://docs.djangoproject.com/en/dev/ref/models/querysets/#queryset-api) offers the following syntax:

Entry.objects.order_by('blogs_blog.name', 'headline')

preceded by the following explanation: "To order by a field in a different table, add the other table’s name and a dot, like so:"

For the following model definitions

from django.db import models

class Poll(models.Model):
    question = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')
    
    def __unicode__(self):
        return self.question


class Choice(models.Model):
    poll = models.ForeignKey(Poll)
    choices = models.CharField(max_length=200)
    votes = models.IntegerField()
    
    def __unicode__(self):
        return self.choices

with MySQL, for this retrieval example:

c=Choice.objects.order_by("polls_poll.question",'-votes')
list(c)

the result is "OperationalError: (1054, "Unknown column 'polls_poll.question' in 'order clause'" in reply to the following SQL query generated:

SELECT `polls_choice`.`id`, `polls_choice`.`poll_id`, `polls_choice`.`choices`,
`polls_choice`.`votes` FROM `polls_choice` ORDER BY `polls_poll`.question ASC,
 `polls_choice`.`votes` DESC

On the other hand
if one follows the syntax offered in the "mainstream" documentation (​http://www.djandoproject.com/db-api), i.e.,

c=Choice.objects.order_by("poll__question",'-votes')
list(c) 

things do work, with the following SQL query generated:

SELECT `polls_choice`.`id`, `polls_choice`.`poll_id`, `polls_choice`.`choices`,
`polls_choice`.`votes` FROM `polls_choice` INNER JOIN `polls_poll` 
ON (`polls_choice`.`poll_id` = `polls_poll`.`id`) ORDER BY `polls_poll`.`question` ASC, 
`polls_choice`.`votes` DESC

This problem might be related to the one reported in the accepted ticket #2884 (component: Admin interface), solution for which is said to be deferred until after queryset-refactor.

[Jerzy.Ludwichowski@…]

Further to the report: I'm running on the development code (rev 8649).

[Ramiro Morales]

Correct. This is a regression caused by the landing of the documentation refactor (doc-rf) in trunk [8506]
The pre doc-rf documentation about this topic is correct: ​http://www.djangoproject.com/documentation/db-api/#order-by-fields

Accepting the ticket and targeting it to 1.0.

[Malcolm Tredinnick]

Fixed in [8694]

[Jacob]

Milestone 1.0 deleted