Source code for airflow.operators.generic_transfer

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from typing import List, Optional, Sequence, Union

from airflow.hooks.base import BaseHook
from airflow.models import BaseOperator
from airflow.utils.context import Context


[docs]class GenericTransfer(BaseOperator): """ Moves data from a connection to another, assuming that they both provide the required methods in their respective hooks. The source hook needs to expose a `get_records` method, and the destination a `insert_rows` method. This is meant to be used on small-ish datasets that fit in memory. :param sql: SQL query to execute against the source database. (templated) :param destination_table: target table. (templated) :param source_conn_id: source connection :param destination_conn_id: destination connection :param preoperator: sql statement or list of statements to be executed prior to loading the data. (templated) :param insert_args: extra params for `insert_rows` method. """
[docs] template_fields: Sequence[str] = ('sql', 'destination_table', 'preoperator')
[docs] template_ext: Sequence[str] = ( '.sql', '.hql',
)
[docs] template_fields_renderers = {"preoperator": "sql"}
[docs] ui_color = '#b0f07c'
def __init__( self, *, sql: str, destination_table: str, source_conn_id: str, destination_conn_id: str, preoperator: Optional[Union[str, List[str]]] = None, insert_args: Optional[dict] = None, **kwargs, ) -> None: super().__init__(**kwargs) self.sql = sql self.destination_table = destination_table self.source_conn_id = source_conn_id self.destination_conn_id = destination_conn_id self.preoperator = preoperator self.insert_args = insert_args or {}
[docs] def execute(self, context: Context): source_hook = BaseHook.get_hook(self.source_conn_id) destination_hook = BaseHook.get_hook(self.destination_conn_id) self.log.info("Extracting data from %s", self.source_conn_id) self.log.info("Executing: \n %s", self.sql) get_records = getattr(source_hook, 'get_records', None) if not callable(get_records): raise RuntimeError( f"Hook for connection {self.source_conn_id!r} " f"({type(source_hook).__name__}) has no `get_records` method" ) else: results = get_records(self.sql) if self.preoperator: run = getattr(destination_hook, 'run', None) if not callable(run): raise RuntimeError( f"Hook for connection {self.destination_conn_id!r} " f"({type(destination_hook).__name__}) has no `run` method" ) self.log.info("Running preoperator") self.log.info(self.preoperator) run(self.preoperator) insert_rows = getattr(destination_hook, 'insert_rows', None) if not callable(insert_rows): raise RuntimeError( f"Hook for connection {self.destination_conn_id!r} " f"({type(destination_hook).__name__}) has no `insert_rows` method" ) self.log.info("Inserting rows into %s", self.destination_conn_id) insert_rows(table=self.destination_table, rows=results, **self.insert_args)

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