def query_samples(self, filter_expr=None, orderby=None, limit=None):
if limit == 0:
return []
session = self._engine_facade.get_session()
engine = self._engine_facade.get_engine()
query = session.query(
models.Sample.timestamp, models.Sample.recorded_at,
models.Sample.message_id, models.Sample.message_signature,
models.Sample.volume.label('counter_volume'),
models.Meter.name.label('counter_name'),
models.Meter.type.label('counter_type'),
models.Meter.unit.label('counter_unit'), models.Resource.source_id,
models.Resource.user_id, models.Resource.project_id,
models.Resource.resource_metadata,
models.Resource.resource_id).join(
models.Meter, models.Meter.id == models.Sample.meter_id).join(
models.Resource,
models.Resource.internal_id == models.Sample.resource_id)
transformer = sql_utils.QueryTransformer(models.FullSample,
query,
dialect=engine.dialect.name)
if filter_expr is not None:
transformer.apply_filter(filter_expr)
transformer.apply_options(orderby, limit)
return self._retrieve_samples(transformer.get_query())
def query_samples(self, filter_expr=None, orderby=None, limit=None):
if limit == 0:
return []
session = self._engine_facade.get_session()
query = session.query(models.FullSample)
transformer = sql_utils.QueryTransformer(models.FullSample, query)
if filter_expr is not None:
transformer.apply_filter(filter_expr)
transformer.apply_options(orderby, limit)
return self._retrieve_samples(transformer.get_query())
def _retrieve_data(self, filter_expr, orderby, limit, table):
if limit == 0:
return []
session = self._engine_facade.get_session()
query = session.query(table)
transformer = sql_utils.QueryTransformer(table, query)
if filter_expr is not None:
transformer.apply_filter(filter_expr)
transformer.apply_options(orderby,
limit)
retrieve = {models.Alarm: self._retrieve_alarms,
models.AlarmChange: self._retrieve_alarm_history}
return retrieve[table](transformer.get_query())
def get_samples(self, sample_filter, limit=None):
"""Return an iterable of api_models.Samples.
:param sample_filter: Filter.
:param limit: Maximum number of results to return.
"""
if limit == 0:
return []
table = models.MeterSample
session = self._engine_facade.get_session()
query = session.query(table)
query = make_query_from_filter(session,
query,
sample_filter,
require_meter=False)
transformer = sql_utils.QueryTransformer(table, query)
transformer.apply_options(None, limit)
return self._retrieve_samples(transformer.get_query())
