def get_annotation(self, cte):
ancestor_condition = self.build_ancestor_condition(cte)
return ArrayAgg(Case(When(condition=WhenQ(*ancestor_condition),
then=cte.col.pk),
default=Value(None)),
output_field=CharField())
def get_annotation(self, cte):
resource_condition = self.build_topic_condition(F('kind_id'), '!=')
topic_condition = self.build_child_condition(cte)
return Coalesce(
Max(
Case(
# when selected node is not a topic, use its sort_order
When(condition=WhenQ(*resource_condition),
then=F('sort_order')),
# when selected node is a topic, then find max of children
When(condition=WhenQ(*topic_condition),
then=cte.col.sort_order),
default=Value(None))),
Value(1),
output_field=IntegerField())
def get_annotation(self, cte):
resource_condition = self.build_topic_condition(F('kind_id'), '!=')
topic_condition = self.build_topic_condition(cte.col.kind_id, '!=')
topic_condition += self.build_descendant_condition(cte)
return Count(
Case(
# when selected node is not a topic, then count = 1
When(condition=WhenQ(*resource_condition),
then=F('content_id')),
# when it is a topic, then count descendants
When(condition=WhenQ(*topic_condition),
then=cte.col.content_id),
default=Value(None)),
distinct=True)
def get_annotation(self, cte):
topic_condition = self.build_topic_condition(F('kind_id'))
topic_condition += self.build_descendant_condition(cte)
topic_condition += self.build_coach_condition(cte.col.role_visibility)
resource_condition = self.build_topic_condition(F('kind_id'), '!=')
resource_condition += self.build_coach_condition(F('role_visibility'))
return Count(
Case(
# when selected node is a coach topic, then count descendent content_id's
When(condition=WhenQ(*topic_condition),
then=cte.col.content_id),
# when selected node is not a topic, count its content_id
When(condition=WhenQ(*resource_condition),
then=F('content_id')),
default=Value(None)),
distinct=True)
def get_annotation(self, cte):
resource_condition = self.build_topic_condition(F('kind_id'), '!=')
whens = [
# when selected node is not a topic, just use its changed status
When(condition=WhenQ(*resource_condition), then=F('changed')),
]
if self.include_self:
# when selected node is a topic and it's changed and including self, then return that
whens.append(
When(condition=WhenQ(*[F('changed')]), then=F('changed')))
return Coalesce(
Case(
*whens,
# fallback to aggregating descendant changed status when a unchanged topic
default=BoolOr(cte.col.changed)),
Value(False),
output_field=BooleanField())
def get_annotation(self, cte=None):
"""
@see MPTTModel.get_descendant_count()
"""
return Max(
Case(
# when selected node is topic, use algorithm to get descendant count
When(
condition=WhenQ(*self.build_topic_condition(F('kind_id'))),
then=(F('rght') - F('lft') - Value(1)) / Value(2)),
# integer division floors the result in postgres
default=Value(1)))
def build(self):
"""
Creates special nested CTE since all other metadata works of nodes, and joining on multiple
file records would produce incorrect result for resource sizes due to summing.
"""
files_cte = FileMetadataCTE(self.query)
files_cte.add_columns(('file_size', 'checksum'))
resource_condition = BooleanComparison(F('kind_id'), '!=',
Value(content_kinds.TOPIC))
q = files_cte.join(self.query).annotate(resource_size=Sum(
Case(
# aggregate file_size when selected node is not a topic
When(
condition=WhenQ(resource_condition),
then=Coalesce(files_cte.col.file_size, Value(0)),
),
default=Value(0)),
output_field=IntegerField()))
return With(q.values(*set(self.columns)), name='resource_size_cte')