[1.2.X] Some small fixes to DB optimization docs.
Backport of [15122] from trunk. git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15123 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
parent
2d854539c3
commit
fa4ac6f80c
|
@ -191,7 +191,7 @@ Don't overuse ``count()`` and ``exists()``
|
|||
|
||||
If you are going to need other data from the QuerySet, just evaluate it.
|
||||
|
||||
For example, assuming an Email class that has a ``body`` attribute and a
|
||||
For example, assuming an Email model that has a ``body`` attribute and a
|
||||
many-to-many relation to User, the following template code is optimal:
|
||||
|
||||
.. code-block:: html+django
|
||||
|
@ -212,7 +212,8 @@ many-to-many relation to User, the following template code is optimal:
|
|||
|
||||
It is optimal because:
|
||||
|
||||
1. Since QuerySets are lazy, this does no database if 'display_inbox' is False.
|
||||
1. Since QuerySets are lazy, this does no database queries if 'display_inbox'
|
||||
is False.
|
||||
|
||||
#. Use of ``with`` means that we store ``user.emails.all`` in a variable for
|
||||
later use, allowing its cache to be re-used.
|
||||
|
|
Loading…
Reference in New Issue