# -*- coding: utf-8 -*-
#
# Licensed 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.
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import logging
from airflow.contrib.hooks.bigquery_hook import BigQueryHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
[docs]class BigQueryToCloudStorageOperator(BaseOperator):
"""
Transfers a BigQuery table to a Google Cloud Storage bucket.
"""
template_fields = ('source_project_dataset_table', 'destination_cloud_storage_uris')
template_ext = ('.sql',)
ui_color = '#e4e6f0'
@apply_defaults
def __init__(
self,
source_project_dataset_table,
destination_cloud_storage_uris,
compression='NONE',
export_format='CSV',
field_delimiter=',',
print_header=True,
bigquery_conn_id='bigquery_default',
delegate_to=None,
*args,
**kwargs):
"""
Create a new BigQueryToCloudStorage to move data from BigQuery to
Google Cloud Storage. See here:
https://cloud.google.com/bigquery/docs/reference/v2/jobs
For more details about these parameters.
:param source_project_dataset_table: The dotted
(<project>.|<project>:)<dataset>.<table> BigQuery table to use as the source
data. If <project> is not included, project will be the project defined in
the connection json.
:type source_project_dataset_table: string
:param destination_cloud_storage_uris: The destination Google Cloud
Storage URI (e.g. gs://some-bucket/some-file.txt). Follows
convention defined here:
https://cloud.google.com/bigquery/exporting-data-from-bigquery#exportingmultiple
:type destination_cloud_storage_uris: list
:param compression: Type of compression to use.
:type compression: string
:param export_format: File format to export.
:type field_delimiter: string
:param field_delimiter: The delimiter to use when extracting to a CSV.
:type field_delimiter: string
:param print_header: Whether to print a header for a CSV file extract.
:type print_header: boolean
:param bigquery_conn_id: reference to a specific BigQuery hook.
:type bigquery_conn_id: string
:param delegate_to: The account to impersonate, if any.
For this to work, the service account making the request must have domain-wide
delegation enabled.
:type delegate_to: string
"""
super(BigQueryToCloudStorageOperator, self).__init__(*args, **kwargs)
self.source_project_dataset_table = source_project_dataset_table
self.destination_cloud_storage_uris = destination_cloud_storage_uris
self.compression = compression
self.export_format = export_format
self.field_delimiter = field_delimiter
self.print_header = print_header
self.bigquery_conn_id = bigquery_conn_id
self.delegate_to = delegate_to
def execute(self, context):
logging.info('Executing extract of %s into: %s',
self.source_project_dataset_table,
self.destination_cloud_storage_uris)
hook = BigQueryHook(bigquery_conn_id=self.bigquery_conn_id,
delegate_to=self.delegate_to)
conn = hook.get_conn()
cursor = conn.cursor()
cursor.run_extract(
self.source_project_dataset_table,
self.destination_cloud_storage_uris,
self.compression,
self.export_format,
self.field_delimiter,
self.print_header)