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Added note to docs/db-api.txt about 'depth' being new in Django development version 

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4649 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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Adrian Holovaty 2007-02-28 19:42:29 +00:00
parent 37c66a0999
commit a81a6e9abe
1 changed files with 3 additions and 1 deletions
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docs/db-api.txt
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@ -596,7 +596,7 @@ related ``Person`` *and* the related ``City``::
Note that ``select_related()`` does not follow foreign keys that have
``null=True``.
Usually, using ``select_related()`` can vastly improve performance since your
Usually, using ``select_related()`` can vastly improve performance because your
app can avoid many database calls. However, in situations with deeply nested
sets of relationships ``select_related()`` can sometimes end up following "too
many" relations, and can generate queries so large that they end up being slow.
@ -608,6 +608,8 @@ follow::
b = Book.objects.select_related(depth=1).get(id=4)
p = b.author # Doesn't hit the database.
c = p.hometown # Requires a database call.
The ``depth`` argument is new in the Django development version.
``extra(select=None, where=None, params=None, tables=None)``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~