Python QuerySet.update方法代码示例

# 需要导入模块: from django.db.models.query import QuerySet [as 别名]
# 或者: from django.db.models.query.QuerySet import update [as 别名]
def formfield(self, **kwargs):
        """Passes ``limit_choices_to`` to field being constructed.

        Only passes it if there is a type that supports related fields.
        This is a similar strategy used to pass the ``queryset`` to the field
        being constructed.
        """
        defaults = {}
        if hasattr(self.rel, 'get_related_field'):
            # If this is a callable, do not invoke it here. Just pass
            # it in the defaults for when the form class will later be
            # instantiated.
            limit_choices_to = self.rel.limit_choices_to
            defaults.update({
                'limit_choices_to': limit_choices_to,
            })
        defaults.update(kwargs)
        return super(RelatedField, self).formfield(**defaults) 

# 需要导入模块: from django.db.models.query import QuerySet [as 别名]
# 或者: from django.db.models.query.QuerySet import update [as 别名]
def __get__(self, instance, instance_type=None):
        if instance is None:
            return self
        try:
            rel_obj = getattr(instance, self.cache_name)
        except AttributeError:
            val = self.field.get_local_related_value(instance)
            if None in val:
                rel_obj = None
            else:
                params = {
                    rh_field.attname: getattr(instance, lh_field.attname)
                    for lh_field, rh_field in self.field.related_fields}
                qs = self.get_queryset(instance=instance)
                extra_filter = self.field.get_extra_descriptor_filter(instance)
                if isinstance(extra_filter, dict):
                    params.update(extra_filter)
                    qs = qs.filter(**params)
                else:
                    qs = qs.filter(extra_filter, **params)
                # Assuming the database enforces foreign keys, this won't fail.
                rel_obj = qs.get()
                if not self.field.rel.multiple:
                    setattr(rel_obj, self.field.rel.get_cache_name(), instance)
            setattr(instance, self.cache_name, rel_obj)
        if rel_obj is None and not self.field.null:
            raise self.RelatedObjectDoesNotExist(
                "%s has no %s." % (self.field.model.__name__, self.field.name)
            )
        else:
            return rel_obj 

# 需要导入模块: from django.db.models.query import QuerySet [as 别名]
# 或者: from django.db.models.query.QuerySet import update [as 别名]
def __set__(self, instance, value):
        super().__set__(instance, value)
        # If the primary key is a link to a parent model and a parent instance
        # is being set, update the value of the inherited pk(s).
        if self.field.primary_key and self.field.remote_field.parent_link:
            opts = instance._meta
            # Inherited primary key fields from this object's base classes.
            inherited_pk_fields = [
                field for field in opts.concrete_fields
                if field.primary_key and field.remote_field
            ]
            for field in inherited_pk_fields:
                rel_model_pk_name = field.remote_field.model._meta.pk.attname
                raw_value = getattr(value, rel_model_pk_name) if value is not None else None
                setattr(instance, rel_model_pk_name, raw_value)