Source code for airflow.contrib.operators.oracle_to_azure_data_lake_transfer

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from airflow.hooks.oracle_hook import OracleHook
from airflow.contrib.hooks.azure_data_lake_hook import AzureDataLakeHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from airflow.utils.file import TemporaryDirectory

import unicodecsv as csv
import os

[docs]class OracleToAzureDataLakeTransfer(BaseOperator): """ Moves data from Oracle to Azure Data Lake. The operator runs the query against Oracle and stores the file locally before loading it into Azure Data Lake. :param filename: file name to be used by the csv file. :type filename: str :param azure_data_lake_conn_id: destination azure data lake connection. :type azure_data_lake_conn_id: str :param azure_data_lake_path: destination path in azure data lake to put the file. :type azure_data_lake_path: str :param oracle_conn_id: source Oracle connection. :type oracle_conn_id: str :param sql: SQL query to execute against the Oracle database. (templated) :type sql: str :param sql_params: Parameters to use in sql query. (templated) :type sql_params: str :param delimiter: field delimiter in the file. :type delimiter: str :param encoding: encoding type for the file. :type encoding: str :param quotechar: Character to use in quoting. :type quotechar: str :param quoting: Quoting strategy. See unicodecsv quoting for more information. :type quoting: str """
[docs] template_fields = ('filename', 'sql', 'sql_params')
[docs] ui_color = '#e08c8c'
@apply_defaults def __init__( self, filename, azure_data_lake_conn_id, azure_data_lake_path, oracle_conn_id, sql, sql_params=None, delimiter=",", encoding="utf-8", quotechar='"', quoting=csv.QUOTE_MINIMAL, *args, **kwargs): super(OracleToAzureDataLakeTransfer, self).__init__(*args, **kwargs) if sql_params is None: sql_params = {} self.filename = filename self.oracle_conn_id = oracle_conn_id self.sql = sql self.sql_params = sql_params self.azure_data_lake_conn_id = azure_data_lake_conn_id self.azure_data_lake_path = azure_data_lake_path self.delimiter = delimiter self.encoding = encoding self.quotechar = quotechar self.quoting = quoting
[docs] def _write_temp_file(self, cursor, path_to_save): with open(path_to_save, 'wb') as csvfile: csv_writer = csv.writer(csvfile, delimiter=self.delimiter, encoding=self.encoding, quotechar=self.quotechar, quoting=self.quoting) csv_writer.writerow(map(lambda field: field[0], cursor.description)) csv_writer.writerows(cursor) csvfile.flush()
[docs] def execute(self, context): oracle_hook = OracleHook(oracle_conn_id=self.oracle_conn_id) azure_data_lake_hook = AzureDataLakeHook( azure_data_lake_conn_id=self.azure_data_lake_conn_id)"Dumping Oracle query results to local file") conn = oracle_hook.get_conn() cursor = conn.cursor() cursor.execute(self.sql, self.sql_params) with TemporaryDirectory(prefix='airflow_oracle_to_azure_op_') as temp: self._write_temp_file(cursor, os.path.join(temp, self.filename))"Uploading local file to Azure Data Lake") azure_data_lake_hook.upload_file(os.path.join(temp, self.filename), os.path.join(self.azure_data_lake_path, self.filename)) cursor.close() conn.close()

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