# -*- 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.
"""
MySQL to GCS operator.
"""
import base64
import calendar
import sys
from datetime import date, datetime, timedelta
from decimal import Decimal
from MySQLdb.constants import FIELD_TYPE
from airflow.hooks.mysql_hook import MySqlHook
from airflow.utils.decorators import apply_defaults
from airflow.contrib.operators.sql_to_gcs import BaseSQLToGoogleCloudStorageOperator
[docs]PY3 = sys.version_info[0] == 3
[docs]class MySqlToGoogleCloudStorageOperator(BaseSQLToGoogleCloudStorageOperator):
"""Copy data from MySQL to Google cloud storage in JSON or CSV format.
:param mysql_conn_id: Reference to a specific MySQL hook.
:type mysql_conn_id: str
:param ensure_utc: Ensure TIMESTAMP columns exported as UTC. If set to
`False`, TIMESTAMP columns will be exported using the MySQL server's
default timezone.
:type ensure_utc: bool
"""
[docs] type_map = {
FIELD_TYPE.BIT: 'INTEGER',
FIELD_TYPE.DATETIME: 'TIMESTAMP',
FIELD_TYPE.DATE: 'TIMESTAMP',
FIELD_TYPE.DECIMAL: 'FLOAT',
FIELD_TYPE.NEWDECIMAL: 'FLOAT',
FIELD_TYPE.DOUBLE: 'FLOAT',
FIELD_TYPE.FLOAT: 'FLOAT',
FIELD_TYPE.INT24: 'INTEGER',
FIELD_TYPE.LONG: 'INTEGER',
FIELD_TYPE.LONGLONG: 'INTEGER',
FIELD_TYPE.SHORT: 'INTEGER',
FIELD_TYPE.TIME: 'TIME',
FIELD_TYPE.TIMESTAMP: 'TIMESTAMP',
FIELD_TYPE.TINY: 'INTEGER',
FIELD_TYPE.YEAR: 'INTEGER',
}
@apply_defaults
def __init__(self,
mysql_conn_id='mysql_default',
ensure_utc=False,
*args,
**kwargs):
super(MySqlToGoogleCloudStorageOperator, self).__init__(*args, **kwargs)
self.mysql_conn_id = mysql_conn_id
self.ensure_utc = ensure_utc
[docs] def query(self):
"""
Queries mysql and returns a cursor to the results.
"""
mysql = MySqlHook(mysql_conn_id=self.mysql_conn_id)
conn = mysql.get_conn()
cursor = conn.cursor()
if self.ensure_utc:
# Ensure TIMESTAMP results are in UTC
tz_query = "SET time_zone = '+00:00'"
self.log.info('Executing: %s', tz_query)
cursor.execute(tz_query)
self.log.info('Executing: %s', self.sql)
cursor.execute(self.sql)
return cursor
[docs] def field_to_bigquery(self, field):
field_type = self.type_map.get(field[1], "STRING")
# Always allow TIMESTAMP to be nullable. MySQLdb returns None types
# for required fields because some MySQL timestamps can't be
# represented by Python's datetime (e.g. 0000-00-00 00:00:00).
field_mode = "NULLABLE" if field[6] or field_type == "TIMESTAMP" else "REQUIRED"
return {
'name': field[0],
'type': field_type,
'mode': field_mode,
}
[docs] def convert_type(self, value, schema_type):
"""
Takes a value from MySQLdb, and converts it to a value that's safe for
JSON/Google cloud storage/BigQuery. Dates are converted to UTC seconds.
Decimals are converted to floats. Binary type fields are encoded with base64,
as imported BYTES data must be base64-encoded according to Bigquery SQL
date type documentation: https://cloud.google.com/bigquery/data-types
:param value: MySQLdb column value
:type value: Any
:param schema_type: BigQuery data type
:type schema_type: str
"""
if isinstance(value, (datetime, date)):
return calendar.timegm(value.timetuple())
if isinstance(value, timedelta):
return value.total_seconds()
if isinstance(value, Decimal):
return float(value)
if schema_type == "BYTES":
col_val = base64.standard_b64encode(value)
if PY3:
col_val = col_val.decode('ascii')
return col_val
return value