django.contrib.postgres.aggregates.general のソースコード
from django.contrib.postgres.fields import ArrayField, JSONField
from django.db.models.aggregates import Aggregate
from .mixins import OrderableAggMixin
__all__ = [
'ArrayAgg', 'BitAnd', 'BitOr', 'BoolAnd', 'BoolOr', 'JSONBAgg', 'StringAgg',
]
[ドキュメント]class ArrayAgg(OrderableAggMixin, Aggregate):
function = 'ARRAY_AGG'
template = '%(function)s(%(distinct)s%(expressions)s %(ordering)s)'
allow_distinct = True
@property
def output_field(self):
return ArrayField(self.source_expressions[0].output_field)
def convert_value(self, value, expression, connection):
if not value:
return []
return value
[ドキュメント]class JSONBAgg(Aggregate):
function = 'JSONB_AGG'
output_field = JSONField()
def convert_value(self, value, expression, connection):
if not value:
return []
return value
[ドキュメント]class StringAgg(OrderableAggMixin, Aggregate):
function = 'STRING_AGG'
template = "%(function)s(%(distinct)s%(expressions)s, '%(delimiter)s'%(ordering)s)"
allow_distinct = True
def __init__(self, expression, delimiter, **extra):
super().__init__(expression, delimiter=delimiter, **extra)
def convert_value(self, value, expression, connection):
if not value:
return ''
return value