Source code for airflow.providers.microsoft.azure.transfers.oracle_to_azure_data_lake
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from __future__ import annotations
import csv
import os
from tempfile import TemporaryDirectory
from typing import TYPE_CHECKING, Any, Sequence
from airflow.models import BaseOperator
from airflow.providers.microsoft.azure.hooks.data_lake import AzureDataLakeHook
from airflow.providers.oracle.hooks.oracle import OracleHook
if TYPE_CHECKING:
from airflow.utils.context import Context
[docs]class OracleToAzureDataLakeOperator(BaseOperator):
"""
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.
:param azure_data_lake_conn_id: destination azure data lake connection.
:param azure_data_lake_path: destination path in azure data lake to put the file.
:param oracle_conn_id: :ref:`Source Oracle connection <howto/connection:oracle>`.
:param sql: SQL query to execute against the Oracle database. (templated)
:param sql_params: Parameters to use in sql query. (templated)
:param delimiter: field delimiter in the file.
:param encoding: encoding type for the file.
:param quotechar: Character to use in quoting.
:param quoting: Quoting strategy. See csv library for more information.
"""
[docs] template_fields: Sequence[str] = ("filename", "sql", "sql_params")
[docs] template_fields_renderers = {"sql_params": "py"}
def __init__(
self,
*,
filename: str,
azure_data_lake_conn_id: str,
azure_data_lake_path: str,
oracle_conn_id: str,
sql: str,
sql_params: dict | None = None,
delimiter: str = ",",
encoding: str = "utf-8",
quotechar: str = '"',
quoting: int = csv.QUOTE_MINIMAL,
**kwargs,
) -> None:
super().__init__(**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
def _write_temp_file(self, cursor: Any, path_to_save: str | bytes | int) -> None:
with open(path_to_save, "w", encoding=self.encoding) as csvfile:
csv_writer = csv.writer(
csvfile,
delimiter=self.delimiter,
quotechar=self.quotechar,
quoting=self.quoting,
)
csv_writer.writerow(field[0] for field in cursor.description)
csv_writer.writerows(cursor)
csvfile.flush()
[docs] def execute(self, context: Context) -> None:
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)
self.log.info("Dumping Oracle query results to local file")
conn = oracle_hook.get_conn()
cursor = conn.cursor() # type: ignore[attr-defined]
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))
self.log.info("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() # type: ignore[attr-defined]