我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用django.db.models.query_utils.PathInfo()。
def get_path_to_parent(self, parent): """ Return a list of PathInfos containing the path from the current model to the parent model, or an empty list if parent is not a parent of the current model. """ if self.model is parent: return [] # Skip the chain of proxy to the concrete proxied model. proxied_model = self.concrete_model path = [] opts = self for int_model in self.get_base_chain(parent): if int_model is proxied_model: opts = int_model._meta else: final_field = opts.parents[int_model] targets = (final_field.remote_field.get_related_field(),) opts = int_model._meta path.append(PathInfo(final_field.model._meta, opts, targets, final_field, False, True)) return path
def get_path_info(self): opts = self.remote_field.model._meta target = opts.pk return [PathInfo(self.model._meta, opts, (target,), self.remote_field, True, False)]
def get_reverse_path_info(self): opts = self.model._meta from_opts = self.remote_field.model._meta return [PathInfo(from_opts, opts, (opts.pk,), self, not self.unique, False)]
def get_path_info(self): """ Get path from this field to the related model. """ opts = self.remote_field.model._meta from_opts = self.model._meta return [PathInfo(from_opts, opts, self.foreign_related_fields, self, False, True)]
def get_reverse_path_info(self): """ Get path from the related model to this field's model. """ opts = self.model._meta from_opts = self.remote_field.model._meta pathinfos = [PathInfo(from_opts, opts, (opts.pk,), self.remote_field, not self.unique, False)] return pathinfos
def _get_path_info_with_parent(self): """ Return the path that joins the current model through any parent models. The idea is that if you have a GFK defined on a parent model then we need to join the parent model first, then the child model. """ # With an inheritance chain ChildTag -> Tag and Tag defines the # GenericForeignKey, and a TaggedItem model has a GenericRelation to # ChildTag, then we need to generate a join from TaggedItem to Tag # (as Tag.object_id == TaggedItem.pk), and another join from Tag to # ChildTag (as that is where the relation is to). Do this by first # generating a join to the parent model, then generating joins to the # child models. path = [] opts = self.remote_field.model._meta parent_opts = opts.get_field(self.object_id_field_name).model._meta target = parent_opts.pk path.append(PathInfo(self.model._meta, parent_opts, (target,), self.remote_field, True, False)) # Collect joins needed for the parent -> child chain. This is easiest # to do if we collect joins for the child -> parent chain and then # reverse the direction (call to reverse() and use of # field.remote_field.get_path_info()). parent_field_chain = [] while parent_opts != opts: field = opts.get_ancestor_link(parent_opts.model) parent_field_chain.append(field) opts = field.remote_field.model._meta parent_field_chain.reverse() for field in parent_field_chain: path.extend(field.remote_field.get_path_info()) return path
def get_path_info(self): opts = self.remote_field.model._meta object_id_field = opts.get_field(self.object_id_field_name) if object_id_field.model != opts.model: return self._get_path_info_with_parent() else: target = opts.pk return [PathInfo(self.model._meta, opts, (target,), self.remote_field, True, False)]
def get_path_info(self): opts = self.rel.to._meta target = opts.pk return [PathInfo(self.model._meta, opts, (target,), self.rel, True, False)]
def get_reverse_path_info(self): opts = self.model._meta from_opts = self.rel.to._meta return [PathInfo(from_opts, opts, (opts.pk,), self, not self.unique, False)]
