django.contrib.postgres.aggregates.general 源代码

from django.contrib.postgres.fields import ArrayField, JSONField
from django.db.models.aggregates import Aggregate

__all__ = [
    'ArrayAgg', 'BitAnd', 'BitOr', 'BoolAnd', 'BoolOr', 'JSONBAgg', 'StringAgg',
]


[文档]class ArrayAgg(Aggregate): function = 'ARRAY_AGG' template = '%(function)s(%(distinct)s%(expressions)s)' @property def output_field(self): return ArrayField(self.source_expressions[0].output_field) def __init__(self, expression, distinct=False, **extra): super().__init__(expression, distinct='DISTINCT ' if distinct else '', **extra) def convert_value(self, value, expression, connection): if not value: return [] return value
[文档]class BitAnd(Aggregate): function = 'BIT_AND'
[文档]class BitOr(Aggregate): function = 'BIT_OR'
[文档]class BoolAnd(Aggregate): function = 'BOOL_AND'
[文档]class BoolOr(Aggregate): function = 'BOOL_OR'
[文档]class JSONBAgg(Aggregate): function = 'JSONB_AGG' output_field = JSONField() def convert_value(self, value, expression, connection): if not value: return [] return value
[文档]class StringAgg(Aggregate): function = 'STRING_AGG' template = "%(function)s(%(distinct)s%(expressions)s, '%(delimiter)s')" def __init__(self, expression, delimiter, distinct=False, **extra): distinct = 'DISTINCT ' if distinct else '' super().__init__(expression, delimiter=delimiter, distinct=distinct, **extra) def convert_value(self, value, expression, connection): if not value: return '' return value
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