Files
deb-python-cassandra-driver/cqlengine/named.py

123 lines
2.9 KiB
Python

from cqlengine.exceptions import CQLEngineException
from cqlengine.query import AbstractQueryableColumn, SimpleQuerySet
from cqlengine.query import DoesNotExist as _DoesNotExist
from cqlengine.query import MultipleObjectsReturned as _MultipleObjectsReturned
class QuerySetDescriptor(object):
"""
returns a fresh queryset for the given model
it's declared on everytime it's accessed
"""
def __get__(self, obj, model):
""" :rtype: ModelQuerySet """
if model.__abstract__:
raise CQLEngineException('cannot execute queries against abstract models')
return SimpleQuerySet(obj)
def __call__(self, *args, **kwargs):
"""
Just a hint to IDEs that it's ok to call this
:rtype: ModelQuerySet
"""
raise NotImplementedError
class NamedColumn(AbstractQueryableColumn):
"""
A column that is not coupled to a model class, or type
"""
def __init__(self, name):
self.name = name
def __unicode__(self):
return self.name
def _get_column(self):
""" :rtype: NamedColumn """
return self
@property
def db_field_name(self):
return self.name
@property
def cql(self):
return self.get_cql()
def get_cql(self):
return '"{}"'.format(self.name)
def to_database(self, val):
return val
class NamedTable(object):
"""
A Table that is not coupled to a model class
"""
__abstract__ = False
objects = QuerySetDescriptor()
class DoesNotExist(_DoesNotExist): pass
class MultipleObjectsReturned(_MultipleObjectsReturned): pass
def __init__(self, keyspace, name):
self.keyspace = keyspace
self.name = name
def column(self, name):
return NamedColumn(name)
def column_family_name(self, include_keyspace=True):
"""
Returns the column family name if it's been defined
otherwise, it creates it from the module and class name
"""
if include_keyspace:
return '{}.{}'.format(self.keyspace, self.name)
else:
return self.name
def _get_column(self, name):
"""
Returns the column matching the given name
:rtype: Column
"""
return self.column(name)
# def create(self, **kwargs):
# return self.objects.create(**kwargs)
def all(self):
return self.objects.all()
def filter(self, *args, **kwargs):
return self.objects.filter(*args, **kwargs)
def get(self, *args, **kwargs):
return self.objects.get(*args, **kwargs)
class NamedKeyspace(object):
"""
A keyspace
"""
def __init__(self, name):
self.name = name
def table(self, name):
"""
returns a table descriptor with the given
name that belongs to this keyspace
"""
return NamedTable(self.name, name)