| 1 | diff --git a/docs/ref/models/queries.txt b/docs/ref/models/queries.txt
|
|---|
| 2 | index 1eab21c..c01bc79 100644
|
|---|
| 3 | --- a/docs/ref/models/queries.txt
|
|---|
| 4 | +++ b/docs/ref/models/queries.txt
|
|---|
| 5 | @@ -57,6 +57,18 @@ and describe the operation.
|
|---|
| 6 |
|
|---|
| 7 | reporter = Reporters.objects.get(pk=reporter.pk)
|
|---|
| 8 |
|
|---|
| 9 | +.. note::
|
|---|
| 10 | +
|
|---|
| 11 | + The ``F()`` is applied everytime the ``save()`` method gets called.
|
|---|
| 12 | +
|
|---|
| 13 | + reporter.stories_filed = F('stories_filed') + 1
|
|---|
| 14 | + reporter.save()
|
|---|
| 15 | + # other changes
|
|---|
| 16 | + reporter.save()
|
|---|
| 17 | +
|
|---|
| 18 | + The above would cause ``reporter.stories_filed`` to be incrimented twice,
|
|---|
| 19 | + once for each call to ``save()``
|
|---|
| 20 | +
|
|---|
| 21 | As well as being used in operations on single instances as above, ``F()`` can
|
|---|
| 22 | be used on ``QuerySets`` of object instances, with ``update()``. This reduces
|
|---|
| 23 | the two queries we were using above - the ``get()`` and the
|
|---|