def get_config():
db_session = DbSession()
# Prevent expiration after the session is closed or object is made transient or disconnected
db_session.expire_on_commit = False
ccm = None
try:
# Should be only one, return last modified
ccm = db_session.query(ChargerConfigModel) \
.order_by(desc(ChargerConfigModel.modified_at)) \
.first()
# Detach (not transient) from database, allows saving in other Threads
# https://docs.sqlalchemy.org/en/14/orm/session_api.html#sqlalchemy.orm.make_transient_to_detached
make_transient(ccm)
make_transient_to_detached(ccm)
except InvalidRequestError as e:
ChargerConfigModel.__cleanupDbSession(db_session,
ChargerConfigModel.__class__)
except Exception as e:
# Nothing to roll back
ChargerConfigModel.logger.error(
"Could not query from {} table in database".format(
ChargerConfigModel.__tablename__),
exc_info=True)
raise DbException(
"Could not query from {} table in database".format(
ChargerConfigModel.__tablename__))
return ccm
def save(self):
self.logger.debug(".save()")
db_session = DbSession()
# Prevent expiration after the session is closed or object is made transient or disconnected
db_session.expire_on_commit = False
try:
# No need to 'add', committing this class
db_session.add(self)
db_session.commit()
# Keep it detached
make_transient(self)
make_transient_to_detached(self)
except InvalidRequestError as e:
self.logger.error(
".save() - Could not commit to {} table in database".format(
self.__tablename__),
exc_info=True)
self.__cleanupDbSession(db_session, self.__class__.__name__)
except Exception as e:
db_session.rollback()
self.logger.error(
".save() - Could not commit to {} table in database".format(
self.__tablename__),
exc_info=True)
raise DbException(
"Could not commit to {} table in database".format(
self.__tablename__))
def delete(self):
db_session = DbSession()
db_session.expire_on_commit = True
try:
db_session.delete(self)
db_session.commit()
# Keep it detached
make_transient(self)
make_transient_to_detached(self)
except InvalidRequestError as e:
self.__cleanupDbSession(db_session, self.__class__.__name__)
except Exception as e:
db_session.rollback()
self.logger.error(
"Could not delete from {} table in database".format(
self.__tablename__),
exc_info=True)
raise DbException(
"Could not delete from {} table in database".format(
self.__tablename__))
