def get(cls, expression):
"""
Retrieve the model instance matching the given expression.
If the number of matching results is not equal to one, then
a ``ValueError`` will be raised.
:param expression: A boolean expression to filter by.
:returns: The matching :py:class:`Model` instance.
:raises: ``ValueError`` if result set size is not 1.
"""
executor = Executor(cls.database)
result = executor.execute(expression)
if len(result) != 1:
raise ValueError('Got %s results, expected 1.' % len(result))
return cls.load(result._first_or_any(), convert_key=False)
def get(cls, expression):
"""
Retrieve the model instance matching the given expression.
If the number of matching results is not equal to one, then
a ``ValueError`` will be raised.
:param expression: A boolean expression to filter by.
:returns: The matching :py:class:`Model` instance.
:raises: ``ValueError`` if result set size is not 1.
"""
executor = Executor(cls.database)
result = executor.execute(expression)
if len(result) != 1:
raise ValueError('Got %s results, expected 1.' % len(result))
return cls.load(result._first_or_any(), convert_key=False)
def query(cls, expression=None, order_by=None):
"""
Return model instances matching the given expression (if
specified). Additionally, matching instances can be returned
sorted by field value.
Example::
# Get administrators sorted by username.
admin_users = User.query(
(User.admin == True),
order_by=User.username)
# List blog entries newest to oldest.
entries = Entry.query(order_by=Entry.timestamp.desc())
# Perform a complex filter.
values = StatData.query(
(StatData.timestamp < datetime.date.today()) &
((StatData.type == 'pv') | (StatData.type == 'cv')))
:param expression: A boolean expression to filter by.
:param order_by: A field whose value should be used to
sort returned instances.
"""
if expression is not None:
executor = Executor(cls.database)
result = executor.execute(expression)
else:
result = cls._query.all_index()
if order_by is not None:
desc = False
if isinstance(order_by, Desc):
desc = True
order_by = order_by.node
alpha = not isinstance(order_by, _ScalarField)
result = cls.database.sort(
result.key,
by='*->%s' % order_by.name,
alpha=alpha,
desc=desc)
elif isinstance(result, ZSet):
result = result.iterator(reverse=True)
for hash_id in result:
yield cls.load(hash_id, convert_key=False)
def query(cls, expression=None, order_by=None):
"""
Return model instances matching the given expression (if
specified). Additionally, matching instances can be returned
sorted by field value.
Example::
# Get administrators sorted by username.
admin_users = User.query(
(User.admin == True),
order_by=User.username)
# List blog entries newest to oldest.
entries = Entry.query(order_by=Entry.timestamp.desc())
# Perform a complex filter.
values = StatData.query(
(StatData.timestamp < datetime.date.today()) &
((StatData.type == 'pv') | (StatData.type == 'cv')))
:param expression: A boolean expression to filter by.
:param order_by: A field whose value should be used to
sort returned instances.
"""
if expression is not None:
executor = Executor(cls.database)
result = executor.execute(expression)
else:
result = cls._query.all_index()
if order_by is not None:
desc = False
if isinstance(order_by, Desc):
desc = True
order_by = order_by.node
alpha = not isinstance(order_by, _ScalarField)
result = cls.database.sort(
result.key,
by='*->%s' % order_by.name,
alpha=alpha,
desc=desc)
elif isinstance(result, ZSet):
result = result.iterator(reverse=True)
for hash_id in result:
yield cls.load(hash_id, convert_key=False)
def query_delete(cls, expression=None):
"""
Delete model instances matching the given expression (if
specified). If no expression is provided, then all model instances
will be deleted.
:param expression: A boolean expression to filter by.
"""
if expression is not None:
executor = Executor(cls.database)
result = executor.execute(expression)
else:
result = cls._query.all_index()
for hash_id in result:
cls.load(hash_id, convert_key=False).delete()
def query_delete(cls, expression=None):
"""
Delete model instances matching the given expression (if
specified). If no expression is provided, then all model instances
will be deleted.
:param expression: A boolean expression to filter by.
"""
if expression is not None:
executor = Executor(cls.database)
result = executor.execute(expression)
else:
result = cls._query.all_index()
for hash_id in result:
cls.load(hash_id, convert_key=False).delete()
def _search(self, query):
expression = parse(query, self)
if expression is None:
return [(member, 0) for member in self.members]
executor = Executor(self.db)
return executor.execute(expression)
