diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ref/models/instances.txt | 6 | ||||
| -rw-r--r-- | docs/ref/models/querysets.txt | 16 | ||||
| -rw-r--r-- | docs/releases/1.5.txt | 4 |
3 files changed, 26 insertions, 0 deletions
diff --git a/docs/ref/models/instances.txt b/docs/ref/models/instances.txt index 14541ad0d1..b7ae3890cf 100644 --- a/docs/ref/models/instances.txt +++ b/docs/ref/models/instances.txt @@ -386,6 +386,12 @@ perform an update on all fields. Specifying ``update_fields`` will force an update. +When saving a model fetched through deferred model loading +(:meth:`~Model.only()` or :meth:`~Model.defer()`) only the fields loaded from +the DB will get updated. In effect there is an automatic ``update_fields`` in +this case. If you assign or change any deferred field value, these fields will +be added to the updated fields. + Deleting objects ================ diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt index 8c188c67c3..b59b2ece82 100644 --- a/docs/ref/models/querysets.txt +++ b/docs/ref/models/querysets.txt @@ -1110,6 +1110,14 @@ one, doing so will result in an error. reader, is slightly faster and consumes a little less memory in the Python process. +.. versionchanged:: 1.5 + +.. note:: + + When calling :meth:`~Model.save()` for instances with deferred fields, + only the loaded fields will be saved. See :meth:`~Model.save()` for more + details. + only ~~~~ @@ -1154,6 +1162,14 @@ All of the cautions in the note for the :meth:`defer` documentation apply to options. Also note that using :meth:`only` and omitting a field requested using :meth:`select_related` is an error as well. +.. versionchanged:: 1.5 + +.. note:: + + When calling :meth:`~Model.save()` for instances with deferred fields, + only the loaded fields will be saved. See :meth:`~Model.save()` for more + details. + using ~~~~~ diff --git a/docs/releases/1.5.txt b/docs/releases/1.5.txt index 4aeb61af94..2896acb36b 100644 --- a/docs/releases/1.5.txt +++ b/docs/releases/1.5.txt @@ -42,6 +42,10 @@ keyword argument ``update_fields``. By using this argument it is possible to save only a select list of model's fields. This can be useful for performance reasons or when trying to avoid overwriting concurrent changes. +Deferred instances (those loaded by .only() or .defer()) will automatically +save just the loaded fields. If any field is set manually after load, that +field will also get updated on save. + See the :meth:`Model.save() <django.db.models.Model.save()>` documentation for more details. |