100 lines
2.6 KiB
Python
100 lines
2.6 KiB
Python
# Copyright 2013-2016 DataStax, Inc.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
|
|
from cassandra.cqlengine import UnicodeMixin
|
|
|
|
|
|
class QueryOperatorException(Exception):
|
|
pass
|
|
|
|
|
|
class BaseQueryOperator(UnicodeMixin):
|
|
# The symbol that identifies this operator in kwargs
|
|
# ie: colname__<symbol>
|
|
symbol = None
|
|
|
|
# The comparator symbol this operator uses in cql
|
|
cql_symbol = None
|
|
|
|
def __unicode__(self):
|
|
if self.cql_symbol is None:
|
|
raise QueryOperatorException("cql symbol is None")
|
|
return self.cql_symbol
|
|
|
|
@classmethod
|
|
def get_operator(cls, symbol):
|
|
if cls == BaseQueryOperator:
|
|
raise QueryOperatorException("get_operator can only be called from a BaseQueryOperator subclass")
|
|
if not hasattr(cls, 'opmap'):
|
|
cls.opmap = {}
|
|
|
|
def _recurse(klass):
|
|
if klass.symbol:
|
|
cls.opmap[klass.symbol.upper()] = klass
|
|
for subklass in klass.__subclasses__():
|
|
_recurse(subklass)
|
|
pass
|
|
|
|
_recurse(cls)
|
|
try:
|
|
return cls.opmap[symbol.upper()]
|
|
except KeyError:
|
|
raise QueryOperatorException("{0} doesn't map to a QueryOperator".format(symbol))
|
|
|
|
|
|
class BaseWhereOperator(BaseQueryOperator):
|
|
""" base operator used for where clauses """
|
|
|
|
|
|
class EqualsOperator(BaseWhereOperator):
|
|
symbol = 'EQ'
|
|
cql_symbol = '='
|
|
|
|
|
|
class InOperator(EqualsOperator):
|
|
symbol = 'IN'
|
|
cql_symbol = 'IN'
|
|
|
|
|
|
class GreaterThanOperator(BaseWhereOperator):
|
|
symbol = "GT"
|
|
cql_symbol = '>'
|
|
|
|
|
|
class GreaterThanOrEqualOperator(BaseWhereOperator):
|
|
symbol = "GTE"
|
|
cql_symbol = '>='
|
|
|
|
|
|
class LessThanOperator(BaseWhereOperator):
|
|
symbol = "LT"
|
|
cql_symbol = '<'
|
|
|
|
|
|
class LessThanOrEqualOperator(BaseWhereOperator):
|
|
symbol = "LTE"
|
|
cql_symbol = '<='
|
|
|
|
|
|
class BaseAssignmentOperator(BaseQueryOperator):
|
|
""" base operator used for insert and delete statements """
|
|
|
|
|
|
class AssignmentOperator(BaseAssignmentOperator):
|
|
cql_symbol = "="
|
|
|
|
|
|
class AddSymbol(BaseAssignmentOperator):
|
|
cql_symbol = "+"
|