text: # -*- coding: utf-8 -*-
  #
  # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you 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 airflow.models import DagModel, DagRun, errors, Pool, SlaMiss, TaskInstance
  from airflow.utils.db import create_session
  
  
  def clear_db_runs():
      with create_session() as session:
          session.query(DagRun).delete()
          session.query(TaskInstance).delete()
  
  
  def clear_db_dags():
      with create_session() as session:
          session.query(DagModel).delete()
  
  
  def clear_db_sla_miss():
      with create_session() as session:
          session.query(SlaMiss).delete()
  
  
  def clear_db_errors():
      with create_session() as session:
          session.query(errors.ImportError).delete()
  
  
  def clear_db_pools():
      with create_session() as session:
          session.query(Pool).delete()
  