Kod źródłowy modułu django.contrib.postgres.aggregates.general
from django.db.models.aggregates import Aggregate
__all__ = [
'ArrayAgg', 'BitAnd', 'BitOr', 'BoolAnd', 'BoolOr', 'StringAgg',
]
[dokumenty]class ArrayAgg(Aggregate):
function = 'ARRAY_AGG'
def convert_value(self, value, expression, connection, context):
if not value:
return []
return value
[dokumenty]class StringAgg(Aggregate):
function = 'STRING_AGG'
template = "%(function)s(%(expressions)s, '%(delimiter)s')"
def __init__(self, expression, delimiter, **extra):
super(StringAgg, self).__init__(expression, delimiter=delimiter, **extra)
def convert_value(self, value, expression, connection, context):
if not value:
return ''
return value