51 lines
1.2 KiB
Python
51 lines
1.2 KiB
Python
|
"""
|
||
|
|
Various data structures used in query construction.
|
||
|
|
|
||
|
|
Factored out from django.db.models.query so that they can also be used by other
|
||
|
|
modules without getting into circular import difficulties.
|
||
|
|
"""
|
||
|
|
|
||
|
|
from copy import deepcopy
|
||
|
|
|
||
|
|
from django.utils import tree
|
||
|
|
|
||
|
|
class QueryWrapper(object):
|
||
|
|
"""
|
||
|
|
A type that indicates the contents are an SQL fragment and the associate
|
||
|
|
parameters. Can be used to pass opaque data to a where-clause, for example.
|
||
|
|
"""
|
||
|
|
def __init__(self, sql, params):
|
||
|
|
self.data = sql, params
|
||
|
|
|
||
|
|
class Q(tree.Node):
|
||
|
|
"""
|
||
|
|
Encapsulates filters as objects that can then be combined logically (using
|
||
|
|
& and |).
|
||
|
|
"""
|
||
|
|
# Connection types
|
||
|
|
AND = 'AND'
|
||
|
|
OR = 'OR'
|
||
|
|
default = AND
|
||
|
|
|
||
|
|
def __init__(self, *args, **kwargs):
|
||
|
|
super(Q, self).__init__(children=list(args) + kwargs.items())
|
||
|
|
|
||
|
|
def _combine(self, other, conn):
|
||
|
|
if not isinstance(other, Q):
|
||
|
|
raise TypeError(other)
|
||
|
|
obj = deepcopy(self)
|
||
|
|
obj.add(other, conn)
|
||
|
|
return obj
|
||
|
|
|
||
|
|
def __or__(self, other):
|
||
|
|
return self._combine(other, self.OR)
|
||
|
|
|
||
|
|
def __and__(self, other):
|
||
|
|
return self._combine(other, self.AND)
|
||
|
|
|
||
|
|
def __invert__(self):
|
||
|
|
obj = deepcopy(self)
|
||
|
|
obj.negate()
|
||
|
|
return obj
|
||
|
|
|