diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/releases/2.0.txt | 12 | ||||
| -rw-r--r-- | docs/topics/db/queries.txt | 3 |
2 files changed, 15 insertions, 0 deletions
diff --git a/docs/releases/2.0.txt b/docs/releases/2.0.txt index 39df2d891d..044123485d 100644 --- a/docs/releases/2.0.txt +++ b/docs/releases/2.0.txt @@ -314,6 +314,18 @@ If you wish to keep this restriction in the admin when editing users, set admin.site.unregister(User) admin.site.register(User, MyUserAdmin) +``QuerySet.reverse()`` and ``last()`` are prohibited after slicing +------------------------------------------------------------------ + +Calling ``QuerySet.reverse()`` or ``last()`` on a sliced queryset leads to +unexpected results due to the slice being applied after reordering. This is +now prohibited, e.g.:: + + >>> Model.objects.all()[:2].reverse() + Traceback (most recent call last): + ... + TypeError: Cannot reverse a query once a slice has been taken. + Miscellaneous ------------- diff --git a/docs/topics/db/queries.txt b/docs/topics/db/queries.txt index b95173773b..b6263a9f42 100644 --- a/docs/topics/db/queries.txt +++ b/docs/topics/db/queries.txt @@ -361,6 +361,9 @@ every *second* object of the first 10:: >>> Entry.objects.all()[:10:2] +Further filtering or ordering of a sliced queryset is prohibited due to the +ambiguous nature of how that might work. + To retrieve a *single* object rather than a list (e.g. ``SELECT foo FROM bar LIMIT 1``), use a simple index instead of a slice. For example, this returns the first ``Entry`` in the database, after |