mirror of
https://github.com/django/django.git
synced 2024-12-22 17:16:24 +00:00
63 lines
1.7 KiB
Python
63 lines
1.7 KiB
Python
"""
|
|
Specifying ordering
|
|
|
|
Specify default ordering for a model using the ``ordering`` attribute, which
|
|
should be a list or tuple of field names. This tells Django how to order
|
|
``QuerySet`` results.
|
|
|
|
If a field name in ``ordering`` starts with a hyphen, that field will be
|
|
ordered in descending order. Otherwise, it'll be ordered in ascending order.
|
|
The special-case field name ``"?"`` specifies random order.
|
|
|
|
The ordering attribute is not required. If you leave it off, ordering will be
|
|
undefined -- not random, just undefined.
|
|
"""
|
|
|
|
from django.db import models
|
|
|
|
|
|
class Author(models.Model):
|
|
name = models.CharField(max_length=63, null=True, blank=True)
|
|
editor = models.ForeignKey('self', models.CASCADE, null=True)
|
|
|
|
class Meta:
|
|
ordering = ('-pk',)
|
|
|
|
|
|
class Article(models.Model):
|
|
author = models.ForeignKey(Author, models.SET_NULL, null=True)
|
|
second_author = models.ForeignKey(Author, models.SET_NULL, null=True, related_name='+')
|
|
headline = models.CharField(max_length=100)
|
|
pub_date = models.DateTimeField()
|
|
|
|
class Meta:
|
|
ordering = (
|
|
'-pub_date',
|
|
models.F('headline'),
|
|
models.F('author__name').asc(),
|
|
models.OrderBy(models.F('second_author__name')),
|
|
)
|
|
|
|
|
|
class OrderedByAuthorArticle(Article):
|
|
class Meta:
|
|
proxy = True
|
|
ordering = ('author', 'second_author')
|
|
|
|
|
|
class OrderedByFArticle(Article):
|
|
class Meta:
|
|
proxy = True
|
|
ordering = (models.F('author').asc(nulls_first=True), 'id')
|
|
|
|
|
|
class ChildArticle(Article):
|
|
pass
|
|
|
|
|
|
class Reference(models.Model):
|
|
article = models.ForeignKey(OrderedByAuthorArticle, models.CASCADE)
|
|
|
|
class Meta:
|
|
ordering = ('article',)
|