diff options
Diffstat (limited to 'django/db/models/query.py')
| -rw-r--r-- | django/db/models/query.py | 51 |
1 files changed, 29 insertions, 22 deletions
diff --git a/django/db/models/query.py b/django/db/models/query.py index 8163b5b973..3e3753ee5a 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -755,8 +755,9 @@ class QuerySet(AltersData): Insert each of the instances into the database. Do *not* call save() on each of the instances, do not send any pre/post_save signals, and do not set the primary key attribute if it is an - autoincrement field (except if features.can_return_rows_from_bulk_insert=True). - Multi-table models are not supported. + autoincrement field (except if + features.can_return_rows_from_bulk_insert=True). Multi-table models are + not supported. """ # When you bulk insert you don't get the primary keys back (if it's an # autoincrement, except if can_return_rows_from_bulk_insert=True), so @@ -774,8 +775,9 @@ class QuerySet(AltersData): raise ValueError("Batch size must be a positive integer.") # Check that the parents share the same concrete model with the our # model to detect the inheritance pattern ConcreteGrandParent -> - # MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy - # would not identify that case as involving multiple tables. + # MultiTableParent -> ProxyChild. Simply checking + # self.model._meta.proxy would not identify that case as involving + # multiple tables. for parent in self.model._meta.all_parents: if parent._meta.concrete_model is not self.model._meta.concrete_model: raise ValueError("Can't bulk create a multi-table inherited model") @@ -1302,10 +1304,10 @@ class QuerySet(AltersData): def _update(self, values): """ - A version of update() that accepts field objects instead of field names. - Used primarily for model saving and not intended for use by general - code (it requires too much poking around at model internals to be - useful at that level). + A version of update() that accepts field objects instead of field + names. Used primarily for model saving and not intended for use by + general code (it requires too much poking around at model internals to + be useful at that level). """ if self.query.is_sliced: raise TypeError("Cannot update a query once a slice has been taken.") @@ -2365,9 +2367,9 @@ def prefetch_related_objects(model_instances, *related_lookups): # Prepare objects: good_objects = True for obj in obj_list: - # Since prefetching can re-use instances, it is possible to have - # the same instance multiple times in obj_list, so obj might - # already be prepared. + # Since prefetching can re-use instances, it is possible to + # have the same instance multiple times in obj_list, so obj + # might already be prepared. if not hasattr(obj, "_prefetched_objects_cache"): try: obj._prefetched_objects_cache = {} @@ -2376,7 +2378,8 @@ def prefetch_related_objects(model_instances, *related_lookups): # values_list(flat=True), for example (TypeError) or # a QuerySet subclass that isn't returning Model # instances (AttributeError), either in Django or a 3rd - # party. prefetch_related() doesn't make sense, so quit. + # party. prefetch_related() doesn't make sense, so + # quit. good_objects = False break if not good_objects: @@ -2384,8 +2387,9 @@ def prefetch_related_objects(model_instances, *related_lookups): # Descend down tree - # We assume that objects retrieved are homogeneous (which is the premise - # of prefetch_related), so what applies to first object applies to all. + # We assume that objects retrieved are homogeneous (which is the + # premise of prefetch_related), so what applies to first object + # applies to all. first_obj = obj_list[0] to_attr = lookup.get_current_to_attr(level)[0] prefetcher, descriptor, attr_found, is_fetched = get_prefetcher( @@ -2462,8 +2466,8 @@ def prefetch_related_objects(model_instances, *related_lookups): if new_obj is None: continue # We special-case `list` rather than something more generic - # like `Iterable` because we don't want to accidentally match - # user models that define __iter__. + # like `Iterable` because we don't want to accidentally + # match user models that define __iter__. if isinstance(new_obj, list): new_obj_list.extend(new_obj) else: @@ -2528,8 +2532,8 @@ def get_prefetcher(instance, through_attr, to_attr): if through_attr == to_attr: is_fetched = rel_obj_descriptor.is_cached else: - # descriptor doesn't support prefetching, so we go ahead and get - # the attribute on the instance rather than the class to + # descriptor doesn't support prefetching, so we go ahead and + # get the attribute on the instance rather than the class to # support many related managers rel_obj = getattr(instance, through_attr) if hasattr(rel_obj, "get_prefetch_querysets"): @@ -2556,12 +2560,14 @@ def prefetch_one_level(instances, prefetcher, lookup, level): # prefetcher must have a method get_prefetch_querysets() which takes a list # of instances, and returns a tuple: - # (queryset of instances of self.model that are related to passed in instances, + # (queryset of instances of self.model that are related to passed in + # instances, # callable that gets value to be matched for returned instances, # callable that gets value to be matched for passed in instances, # boolean that is True for singly related objects, # cache or field name to assign to, - # boolean that is True when the previous argument is a cache name vs a field name). + # boolean that is True when the previous argument is a cache name vs a + # field name). # The 'values to be matched' must be hashable as they will be used # in a dictionary. @@ -2601,8 +2607,9 @@ def prefetch_one_level(instances, prefetcher, lookup, level): to_attr, as_attr = lookup.get_current_to_attr(level) # Make sure `to_attr` does not conflict with a field. if as_attr and instances: - # We assume that objects retrieved are homogeneous (which is the premise - # of prefetch_related), so what applies to first object applies to all. + # We assume that objects retrieved are homogeneous (which is the + # premise of prefetch_related), so what applies to first object applies + # to all. model = instances[0].__class__ try: model._meta.get_field(to_attr) |