From 96848352f97e8c2deb976ce4c8418c0d0aa6be5e Mon Sep 17 00:00:00 2001 From: Russell Keith-Magee Date: Fri, 8 Jan 2010 00:17:33 +0000 Subject: [PATCH] Added `using` to the list of documented arguments for save() on a model; updated the docs to suggest using ``*args, **kwargs`` when implementing model save methods. Thanks to Jeff Croft for the report. git-svn-id: http://code.djangoproject.com/svn/django/trunk@12118 bcc190cf-cafb-0310-a4f2-bffc1f526a37 --- docs/ref/models/instances.txt | 36 +++++++++++++++++++++++------------ docs/topics/db/models.txt | 26 +++++++++++++++++-------- 2 files changed, 42 insertions(+), 20 deletions(-) diff --git a/docs/ref/models/instances.txt b/docs/ref/models/instances.txt index 5999038979..f2eb54c217 100644 --- a/docs/ref/models/instances.txt +++ b/docs/ref/models/instances.txt @@ -66,15 +66,20 @@ Saving objects To save an object back to the database, call ``save()``: -.. method:: Model.save([force_insert=False, force_update=False]) - -Of course, there are some subtleties; see the sections below. +.. method:: Model.save([force_insert=False, force_update=False, using=DEFAULT_DB_ALIAS]) .. versionadded:: 1.0 + The ``force_insert`` and ``force_update`` arguments were added. -The signature of the ``save()`` method has changed from earlier versions -(``force_insert`` and ``force_update`` have been added). If you are overriding -these methods, be sure to use the correct signature. +.. versionadded:: 1.1 + The ``using`` argument was added. + +If you want customized saving behavior, you can override this +``save()`` method. See :ref:`overriding-model-methods` for more +details. + +The model save process also has some subtleties; see the sections +below. Auto-incrementing primary keys ------------------------------ @@ -265,14 +270,21 @@ For more details, see the documentation on :ref:`F() expressions Deleting objects ================ -.. method:: Model.delete() +.. method:: Model.delete([using=DEFAULT_DB_ALIAS]) - Issues a SQL ``DELETE`` for the object. This only deletes the object in the - database; the Python instance will still be around, and will still have data - in its fields. +.. versionadded:: 1.1 + The ``using`` argument was added. - For more details, including how to delete objects in bulk, see - :ref:`topics-db-queries-delete`. +Issues a SQL ``DELETE`` for the object. This only deletes the object +in the database; the Python instance will still be around, and will +still have data in its fields. + +For more details, including how to delete objects in bulk, see +:ref:`topics-db-queries-delete`. + +If you want customized deletion behavior, you can override this +``delete()`` method. See :ref:`overriding-model-methods` for more +details. .. _model-instance-methods: diff --git a/docs/topics/db/models.txt b/docs/topics/db/models.txt index a28e7e8805..1e69009827 100644 --- a/docs/topics/db/models.txt +++ b/docs/topics/db/models.txt @@ -707,6 +707,8 @@ below -- but there are a couple that you'll almost always want to define: Any object that has a URL that uniquely identifies it should define this method. +.. _overriding-model-methods: + Overriding predefined model methods ----------------------------------- @@ -726,9 +728,9 @@ to happen whenever you save an object. For example (see name = models.CharField(max_length=100) tagline = models.TextField() - def save(self, force_insert=False, force_update=False): + def save(self, *args, **kwargs): do_something() - super(Blog, self).save(force_insert, force_update) # Call the "real" save() method. + super(Blog, self).save(*args, **kwargs) # Call the "real" save() method. do_something_else() You can also prevent saving:: @@ -737,16 +739,24 @@ You can also prevent saving:: name = models.CharField(max_length=100) tagline = models.TextField() - def save(self, force_insert=False, force_update=False): + def save(self, *args, **kwargs): if self.name == "Yoko Ono's blog": return # Yoko shall never have her own blog! else: - super(Blog, self).save(force_insert, force_update) # Call the "real" save() method. + super(Blog, self).save(*args, **kwargs) # Call the "real" save() method. -It's important to remember to call the superclass method -- that's that -``super(Blog, self).save()`` business -- to ensure that the object still gets -saved into the database. If you forget to call the superclass method, the -default behavior won't happen and the database won't get touched. +It's important to remember to call the superclass method -- that's +that ``super(Blog, self).save(*args, **kwargs)`` business -- to ensure +that the object still gets saved into the database. If you forget to +call the superclass method, the default behavior won't happen and the +database won't get touched. + +It's also important that you pass through the arguments that can be +passed to the model method -- that's what the ``*args, **kwargs`` bit +does. Django will, from time to time, extend the capabilities of +built-in model methods, adding new arguments. If you use ``*args, +**kwargs`` in your method definitions, you are guaranteed that your +code will automatically support those arguments when they are added. Executing custom SQL --------------------