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Fixed #25508 -- Modified QuerySet.__repr__() to disambiguate it from a list.
This commit is contained in:
Tim Graham
parent
3543fec3b7
commit
e0837f2cb1
20 changed files with 185 additions and 184 deletions
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@ -79,7 +79,7 @@ In a hurry? Here's how to do common aggregate queries, assuming the models above
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>>> from django.db.models import Count
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>>> pubs = Publisher.objects.annotate(num_books=Count('book'))
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>>> pubs
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[<Publisher BaloneyPress>, <Publisher SalamiPress>, ...]
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<QuerySet [<Publisher: BaloneyPress>, <Publisher: SalamiPress>, ...]>
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>>> pubs[0].num_books
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73
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@ -93,36 +93,36 @@ Create and add a ``Publication`` to an ``Article`` in one step using
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``Article`` objects have access to their related ``Publication`` objects::
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>>> a1.publications.all()
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> a2.publications.all()
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[<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]>
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``Publication`` objects have access to their related ``Article`` objects::
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>>> p2.article_set.all()
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[<Article: NASA uses Python>]
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<QuerySet [<Article: NASA uses Python>]>
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>>> p1.article_set.all()
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Publication.objects.get(id=4).article_set.all()
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[<Article: NASA uses Python>]
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<QuerySet [<Article: NASA uses Python>]>
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Many-to-many relationships can be queried using :ref:`lookups across
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relationships <lookups-that-span-relationships>`::
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>>> Article.objects.filter(publications__id=1)
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications__pk=1)
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications=1)
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications=p1)
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications__title__startswith="Science")
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[<Article: NASA uses Python>, <Article: NASA uses Python>]
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<QuerySet [<Article: NASA uses Python>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications__title__startswith="Science").distinct()
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[<Article: NASA uses Python>]
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<QuerySet [<Article: NASA uses Python>]>
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The :meth:`~django.db.models.query.QuerySet.count` function respects
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:meth:`~django.db.models.query.QuerySet.distinct` as well::
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@ -134,57 +134,57 @@ The :meth:`~django.db.models.query.QuerySet.count` function respects
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1
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>>> Article.objects.filter(publications__in=[1,2]).distinct()
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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>>> Article.objects.filter(publications__in=[p1,p2]).distinct()
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[<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA uses Python>]>
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Reverse m2m queries are supported (i.e., starting at the table that doesn't have
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a :class:`~django.db.models.ManyToManyField`)::
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>>> Publication.objects.filter(id=1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(pk=1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(article__headline__startswith="NASA")
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[<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]>
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>>> Publication.objects.filter(article__id=1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(article__pk=1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(article=1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(article=a1)
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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>>> Publication.objects.filter(article__in=[1,2]).distinct()
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[<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]>
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>>> Publication.objects.filter(article__in=[a1,a2]).distinct()
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[<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>, <Publication: The Python Journal>]>
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Excluding a related item works as you would expect, too (although the SQL
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involved is a little complex)::
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>>> Article.objects.exclude(publications=p2)
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[<Article: Django lets you build Web apps easily>]
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<QuerySet [<Article: Django lets you build Web apps easily>]>
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If we delete a ``Publication``, its ``Articles`` won't be able to access it::
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>>> p1.delete()
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>>> Publication.objects.all()
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[<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: Science News>, <Publication: Science Weekly>]>
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>>> a1 = Article.objects.get(pk=1)
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>>> a1.publications.all()
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[]
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<QuerySet []>
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If we delete an ``Article``, its ``Publications`` won't be able to access it::
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>>> a2.delete()
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>>> Article.objects.all()
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[<Article: Django lets you build Web apps easily>]
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<QuerySet [<Article: Django lets you build Web apps easily>]>
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>>> p2.article_set.all()
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[]
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<QuerySet []>
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Adding via the 'other' end of an m2m::
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@ -192,61 +192,61 @@ Adding via the 'other' end of an m2m::
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>>> a4.save()
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>>> p2.article_set.add(a4)
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>>> p2.article_set.all()
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[<Article: NASA finds intelligent life on Earth>]
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<QuerySet [<Article: NASA finds intelligent life on Earth>]>
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>>> a4.publications.all()
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[<Publication: Science News>]
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<QuerySet [<Publication: Science News>]>
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Adding via the other end using keywords::
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>>> new_article = p2.article_set.create(headline='Oxygen-free diet works wonders')
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>>> p2.article_set.all()
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[<Article: NASA finds intelligent life on Earth>, <Article: Oxygen-free diet works wonders>]
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<QuerySet [<Article: NASA finds intelligent life on Earth>, <Article: Oxygen-free diet works wonders>]>
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>>> a5 = p2.article_set.all()[1]
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>>> a5.publications.all()
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[<Publication: Science News>]
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<QuerySet [<Publication: Science News>]>
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Removing ``Publication`` from an ``Article``::
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>>> a4.publications.remove(p2)
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>>> p2.article_set.all()
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[<Article: Oxygen-free diet works wonders>]
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<QuerySet [<Article: Oxygen-free diet works wonders>]>
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>>> a4.publications.all()
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[]
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<QuerySet []>
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And from the other end::
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>>> p2.article_set.remove(a5)
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>>> p2.article_set.all()
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[]
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<QuerySet []>
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>>> a5.publications.all()
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[]
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<QuerySet []>
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Relation sets can be assigned. Assignment clears any existing set members::
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>>> a4.publications.all()
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[<Publication: Science News>]
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<QuerySet [<Publication: Science News>]>
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>>> a4.publications = [p3]
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>>> a4.publications.all()
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[<Publication: Science Weekly>]
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<QuerySet [<Publication: Science Weekly>]>
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Relation sets can be cleared::
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>>> p2.article_set.clear()
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>>> p2.article_set.all()
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[]
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<QuerySet []>
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And you can clear from the other end::
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>>> p2.article_set.add(a4, a5)
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>>> p2.article_set.all()
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[<Article: NASA finds intelligent life on Earth>, <Article: Oxygen-free diet works wonders>]
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<QuerySet [<Article: NASA finds intelligent life on Earth>, <Article: Oxygen-free diet works wonders>]>
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>>> a4.publications.all()
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[<Publication: Science News>, <Publication: Science Weekly>]
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<QuerySet [<Publication: Science News>, <Publication: Science Weekly>]>
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>>> a4.publications.clear()
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>>> a4.publications.all()
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[]
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<QuerySet []>
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>>> p2.article_set.all()
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[<Article: Oxygen-free diet works wonders>]
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<QuerySet [<Article: Oxygen-free diet works wonders>]>
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Recreate the ``Article`` and ``Publication`` we have deleted::
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@ -261,17 +261,17 @@ go::
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>>> Publication.objects.filter(title__startswith='Science').delete()
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>>> Publication.objects.all()
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[<Publication: Highlights for Children>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: The Python Journal>]>
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>>> Article.objects.all()
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[<Article: Django lets you build Web apps easily>, <Article: NASA finds intelligent life on Earth>, <Article: NASA uses Python>, <Article: Oxygen-free diet works wonders>]
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<QuerySet [<Article: Django lets you build Web apps easily>, <Article: NASA finds intelligent life on Earth>, <Article: NASA uses Python>, <Article: Oxygen-free diet works wonders>]>
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>>> a2.publications.all()
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[<Publication: The Python Journal>]
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<QuerySet [<Publication: The Python Journal>]>
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Bulk delete some articles - references to deleted objects should go::
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>>> q = Article.objects.filter(headline__startswith='Django')
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>>> print(q)
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[<Article: Django lets you build Web apps easily>]
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<QuerySet [<Article: Django lets you build Web apps easily>]>
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>>> q.delete()
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After the :meth:`~django.db.models.query.QuerySet.delete`, the
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@ -279,9 +279,9 @@ After the :meth:`~django.db.models.query.QuerySet.delete`, the
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referenced objects should be gone::
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>>> print(q)
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[]
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<QuerySet []>
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>>> p1.article_set.all()
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[<Article: NASA uses Python>]
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<QuerySet [<Article: NASA uses Python>]>
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An alternate to calling
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:meth:`~django.db.models.fields.related.RelatedManager.clear` is to assign the
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@ -289,11 +289,11 @@ empty set::
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>>> p1.article_set = []
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>>> p1.article_set.all()
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[]
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<QuerySet []>
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>>> a2.publications = [p1, new_publication]
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>>> a2.publications.all()
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[<Publication: Highlights for Children>, <Publication: The Python Journal>]
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<QuerySet [<Publication: Highlights for Children>, <Publication: The Python Journal>]>
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>>> a2.publications = []
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>>> a2.publications.all()
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[]
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<QuerySet []>
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@ -90,7 +90,7 @@ Create a new article, and add it to the article set::
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>>> new_article2.reporter.id
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1
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>>> r.article_set.all()
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[<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]>
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Add the same article to a different article set - check that it moves::
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@ -108,9 +108,9 @@ Adding an object of the wrong type raises TypeError::
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TypeError: 'Article' instance expected
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>>> r.article_set.all()
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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>>> r2.article_set.all()
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[<Article: Paul's story>]
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<QuerySet [<Article: Paul's story>]>
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>>> r.article_set.count()
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2
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@ -126,56 +126,56 @@ Use double underscores to separate relationships.
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This works as many levels deep as you want. There's no limit. For example::
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>>> r.article_set.filter(headline__startswith='This')
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[<Article: This is a test>]
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<QuerySet [<Article: This is a test>]>
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# Find all Articles for any Reporter whose first name is "John".
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>>> Article.objects.filter(reporter__first_name='John')
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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Exact match is implied here::
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>>> Article.objects.filter(reporter__first_name='John')
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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Query twice over the related field. This translates to an AND condition in the
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WHERE clause::
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>>> Article.objects.filter(reporter__first_name='John', reporter__last_name='Smith')
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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For the related lookup you can supply a primary key value or pass the related
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object explicitly::
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>>> Article.objects.filter(reporter__pk=1)
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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>>> Article.objects.filter(reporter=1)
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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>>> Article.objects.filter(reporter=r)
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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>>> Article.objects.filter(reporter__in=[1,2]).distinct()
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[<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]>
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>>> Article.objects.filter(reporter__in=[r,r2]).distinct()
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[<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]>
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You can also use a queryset instead of a literal list of instances::
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>>> Article.objects.filter(reporter__in=Reporter.objects.filter(first_name='John')).distinct()
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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Querying in the opposite direction::
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>>> Reporter.objects.filter(article__pk=1)
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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>>> Reporter.objects.filter(article=1)
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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>>> Reporter.objects.filter(article=a)
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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>>> Reporter.objects.filter(article__headline__startswith='This')
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[<Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>]>
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>>> Reporter.objects.filter(article__headline__startswith='This').distinct()
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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Counting in the opposite direction works in conjunction with distinct()::
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@ -187,30 +187,30 @@ Counting in the opposite direction works in conjunction with distinct()::
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Queries can go round in circles::
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>>> Reporter.objects.filter(article__reporter__first_name__startswith='John')
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[<Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>, <Reporter: John Smith>]>
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>>> Reporter.objects.filter(article__reporter__first_name__startswith='John').distinct()
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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>>> Reporter.objects.filter(article__reporter=r).distinct()
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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If you delete a reporter, his articles will be deleted (assuming that the
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ForeignKey was defined with :attr:`django.db.models.ForeignKey.on_delete` set to
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``CASCADE``, which is the default)::
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>>> Article.objects.all()
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[<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>]>
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>>> Reporter.objects.order_by('first_name')
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[<Reporter: John Smith>, <Reporter: Paul Jones>]
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<QuerySet [<Reporter: John Smith>, <Reporter: Paul Jones>]>
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>>> r2.delete()
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>>> Article.objects.all()
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[<Article: John's second story>, <Article: This is a test>]
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<QuerySet [<Article: John's second story>, <Article: This is a test>]>
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>>> Reporter.objects.order_by('first_name')
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[<Reporter: John Smith>]
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<QuerySet [<Reporter: John Smith>]>
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You can delete using a JOIN in the query::
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>>> Reporter.objects.filter(article__headline__startswith='This').delete()
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>>> Reporter.objects.all()
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[]
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<QuerySet []>
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>>> Article.objects.all()
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[]
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<QuerySet []>
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@ -106,13 +106,13 @@ that there are two restaurants - Ace Hardware the Restaurant was created in the
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call to r.place = p2::
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>>> Restaurant.objects.all()
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[<Restaurant: Demon Dogs the restaurant>, <Restaurant: Ace Hardware the restaurant>]
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<QuerySet [<Restaurant: Demon Dogs the restaurant>, <Restaurant: Ace Hardware the restaurant>]>
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||||
|
||||
Place.objects.all() returns all Places, regardless of whether they have
|
||||
Restaurants::
|
||||
|
||||
>>> Place.objects.order_by('name')
|
||||
[<Place: Ace Hardware the place>, <Place: Demon Dogs the place>]
|
||||
<QuerySet [<Place: Ace Hardware the place>, <Place: Demon Dogs the place>]>
|
||||
|
||||
You can query the models using :ref:`lookups across relationships <lookups-that-span-relationships>`::
|
||||
|
||||
|
|
@ -121,9 +121,9 @@ You can query the models using :ref:`lookups across relationships <lookups-that-
|
|||
>>> Restaurant.objects.get(place__pk=1)
|
||||
<Restaurant: Demon Dogs the restaurant>
|
||||
>>> Restaurant.objects.filter(place__name__startswith="Demon")
|
||||
[<Restaurant: Demon Dogs the restaurant>]
|
||||
<QuerySet [<Restaurant: Demon Dogs the restaurant>]>
|
||||
>>> Restaurant.objects.exclude(place__address__contains="Ashland")
|
||||
[<Restaurant: Demon Dogs the restaurant>]
|
||||
<QuerySet [<Restaurant: Demon Dogs the restaurant>]>
|
||||
|
||||
This of course works in reverse::
|
||||
|
||||
|
|
@ -146,6 +146,6 @@ Add a Waiter to the Restaurant::
|
|||
Query the waiters::
|
||||
|
||||
>>> Waiter.objects.filter(restaurant__place=p1)
|
||||
[<Waiter: Joe the waiter at Demon Dogs the restaurant>]
|
||||
<QuerySet [<Waiter: Joe the waiter at Demon Dogs the restaurant>]>
|
||||
>>> Waiter.objects.filter(restaurant__place__name__startswith="Demon")
|
||||
[<Waiter: Joe the waiter at Demon Dogs the restaurant>]
|
||||
<QuerySet [<Waiter: Joe the waiter at Demon Dogs the restaurant>]>
|
||||
|
|
|
|||
|
|
@ -501,14 +501,14 @@ the intermediate model::
|
|||
... invite_reason="Needed a new drummer.")
|
||||
>>> m1.save()
|
||||
>>> beatles.members.all()
|
||||
[<Person: Ringo Starr>]
|
||||
<QuerySet [<Person: Ringo Starr>]>
|
||||
>>> ringo.group_set.all()
|
||||
[<Group: The Beatles>]
|
||||
<QuerySet [<Group: The Beatles>]>
|
||||
>>> m2 = Membership.objects.create(person=paul, group=beatles,
|
||||
... date_joined=date(1960, 8, 1),
|
||||
... invite_reason="Wanted to form a band.")
|
||||
>>> beatles.members.all()
|
||||
[<Person: Ringo Starr>, <Person: Paul McCartney>]
|
||||
<QuerySet [<Person: Ringo Starr>, <Person: Paul McCartney>]>
|
||||
|
||||
Unlike normal many-to-many fields, you *can't* use ``add``, ``create``,
|
||||
or assignment (i.e., ``beatles.members = [...]``) to create relationships::
|
||||
|
|
@ -537,7 +537,7 @@ used to remove all many-to-many relationships for an instance::
|
|||
>>> beatles.members.clear()
|
||||
>>> # Note that this deletes the intermediate model instances
|
||||
>>> Membership.objects.all()
|
||||
[]
|
||||
<QuerySet []>
|
||||
|
||||
Once you have established the many-to-many relationships by creating instances
|
||||
of your intermediate model, you can issue queries. Just as with normal
|
||||
|
|
@ -546,7 +546,7 @@ many-to-many-related model::
|
|||
|
||||
# Find all the groups with a member whose name starts with 'Paul'
|
||||
>>> Group.objects.filter(members__name__startswith='Paul')
|
||||
[<Group: The Beatles>]
|
||||
<QuerySet [<Group: The Beatles>]>
|
||||
|
||||
As you are using an intermediate model, you can also query on its attributes::
|
||||
|
||||
|
|
@ -554,7 +554,7 @@ As you are using an intermediate model, you can also query on its attributes::
|
|||
>>> Person.objects.filter(
|
||||
... group__name='The Beatles',
|
||||
... membership__date_joined__gt=date(1961,1,1))
|
||||
[<Person: Ringo Starr]
|
||||
<QuerySet [<Person: Ringo Starr]>
|
||||
|
||||
If you need to access a membership's information you may do so by directly
|
||||
querying the ``Membership`` model::
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue