Source code for airflow.providers.common.sql.operators.generic_transfer

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# 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
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#   http://www.apache.org/licenses/LICENSE-2.0
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# software distributed under the License is distributed on an
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# under the License.
from __future__ import annotations

from collections.abc import Sequence
from functools import cached_property
from typing import TYPE_CHECKING, Any

from airflow.exceptions import AirflowException
from airflow.hooks.base import BaseHook
from airflow.models import BaseOperator
from airflow.providers.common.sql.hooks.sql import DbApiHook
from airflow.providers.common.sql.triggers.sql import SQLExecuteQueryTrigger

if TYPE_CHECKING:
    import jinja2

    try:
        from airflow.sdk.definitions.context import Context
    except ImportError:
        # TODO: Remove once provider drops support for Airflow 2
        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. (templated)
    :param source_hook_params: source hook parameters.
    :param destination_conn_id: destination connection. (templated)
    :param destination_hook_params: destination hook parameters.
    :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.
    :param page_size: number of records to be read in paginated mode (optional).
    """


[docs]
    template_fields: Sequence[str] = (
        "source_conn_id",
        "destination_conn_id",
        "sql",
        "destination_table",
        "preoperator",
        "insert_args",
    )


[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,
        source_hook_params: dict | None = None,
        destination_conn_id: str,
        destination_hook_params: dict | None = None,
        preoperator: str | list[str] | None = None,
        insert_args: dict | None = None,
        page_size: int | None = None,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)

[docs]
        self.sql = sql


[docs]
        self.destination_table = destination_table


[docs]
        self.source_conn_id = source_conn_id


[docs]
        self.source_hook_params = source_hook_params


[docs]
        self.destination_conn_id = destination_conn_id


[docs]
        self.destination_hook_params = destination_hook_params


[docs]
        self.preoperator = preoperator


[docs]
        self.insert_args = insert_args or {}


[docs]
        self.page_size = page_size

        self._paginated_sql_statement_format = kwargs.get(
            "paginated_sql_statement_format", "{} LIMIT {} OFFSET {}"
        )

    @classmethod

[docs]
    def get_hook(cls, conn_id: str, hook_params: dict | None = None) -> DbApiHook:
        """
        Return DbApiHook for this connection id.

        :param conn_id: connection id
        :param hook_params: hook parameters
        :return: DbApiHook for this connection
        """
        connection = BaseHook.get_connection(conn_id)
        hook = connection.get_hook(hook_params=hook_params)
        if not isinstance(hook, DbApiHook):
            raise RuntimeError(f"Hook for connection {conn_id!r} must be of type {DbApiHook.__name__}")
        return hook


    @cached_property

[docs]
    def source_hook(self) -> DbApiHook:
        return self.get_hook(conn_id=self.source_conn_id, hook_params=self.source_hook_params)


    @cached_property

[docs]
    def destination_hook(self) -> DbApiHook:
        return self.get_hook(conn_id=self.destination_conn_id, hook_params=self.destination_hook_params)



[docs]
    def get_paginated_sql(self, offset: int) -> str:
        """Format the paginated SQL statement using the current format."""
        return self._paginated_sql_statement_format.format(self.sql, self.page_size, offset)



[docs]
    def render_template_fields(
        self,
        context: Context,
        jinja_env: jinja2.Environment | None = None,
    ) -> None:
        super().render_template_fields(context=context, jinja_env=jinja_env)

        # Make sure string are converted to integers
        if isinstance(self.page_size, str):
            self.page_size = int(self.page_size)
        commit_every = self.insert_args.get("commit_every")
        if isinstance(commit_every, str):
            self.insert_args["commit_every"] = int(commit_every)



[docs]
    def execute(self, context: Context):
        if self.preoperator:
            self.log.info("Running preoperator")
            self.log.info(self.preoperator)
            self.destination_hook.run(self.preoperator)

        if self.page_size and isinstance(self.sql, str):
            self.defer(
                trigger=SQLExecuteQueryTrigger(
                    conn_id=self.source_conn_id,
                    hook_params=self.source_hook_params,
                    sql=self.get_paginated_sql(0),
                ),
                method_name=self.execute_complete.__name__,
            )
        else:
            self.log.info("Extracting data from %s", self.source_conn_id)
            self.log.info("Executing: \n %s", self.sql)

            results = self.destination_hook.get_records(self.sql)

            self.log.info("Inserting rows into %s", self.destination_conn_id)
            self.destination_hook.insert_rows(table=self.destination_table, rows=results, **self.insert_args)



[docs]
    def execute_complete(
        self,
        context: Context,
        event: dict[Any, Any] | None = None,
    ) -> Any:
        if event:
            if event.get("status") == "failure":
                raise AirflowException(event.get("message"))

            results = event.get("results")

            if results:
                map_index = context["ti"].map_index
                offset = (
                    context["ti"].xcom_pull(
                        key="offset",
                        task_ids=self.task_id,
                        dag_id=self.dag_id,
                        map_indexes=map_index,
                        default=0,
                    )
                    + self.page_size
                )

                self.log.info("Offset increased to %d", offset)
                self.xcom_push(context=context, key="offset", value=offset)

                self.log.info("Inserting %d rows into %s", len(results), self.destination_conn_id)
                self.destination_hook.insert_rows(
                    table=self.destination_table, rows=results, **self.insert_args
                )
                self.log.info(
                    "Inserting %d rows into %s done!",
                    len(results),
                    self.destination_conn_id,
                )

                self.defer(
                    trigger=SQLExecuteQueryTrigger(
                        conn_id=self.source_conn_id,
                        hook_params=self.source_hook_params,
                        sql=self.get_paginated_sql(offset),
                    ),
                    method_name=self.execute_complete.__name__,
                )
            else:
                self.log.info(
                    "No more rows to fetch into %s; ending transfer.",
                    self.destination_table,
                )