# -*- coding: utf-8 -*-
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# to you under the Apache License, Version 2.0 (the
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from builtins import str
from airflow.hooks.base_hook import BaseHook
from airflow.sensors.base_sensor_operator import BaseSensorOperator
from airflow.utils.decorators import apply_defaults
[docs]class SqlSensor(BaseSensorOperator):
"""
Runs a sql statement until a criteria is met. It will keep trying while
sql returns no row, or if the first cell in (0, '0', '').
:param conn_id: The connection to run the sensor against
:type conn_id: string
:param sql: The sql to run. To pass, it needs to return at least one cell
that contains a non-zero / empty string value.
"""
template_fields = ('sql',)
template_ext = ('.hql', '.sql',)
ui_color = '#7c7287'
@apply_defaults
def __init__(self, conn_id, sql, *args, **kwargs):
self.sql = sql
self.conn_id = conn_id
super(SqlSensor, self).__init__(*args, **kwargs)
[docs] def poke(self, context):
hook = BaseHook.get_connection(self.conn_id).get_hook()
self.log.info('Poking: %s', self.sql)
records = hook.get_records(self.sql)
if not records:
return False
else:
if str(records[0][0]) in ('0', '',):
return False
else:
return True