Source code for airflow.providers.google.cloud.utils.bigquery_get_data

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from __future__ import annotations

import itertools
from typing import TYPE_CHECKING

from google.cloud.bigquery.table import Row, RowIterator

if TYPE_CHECKING:
    from collections.abc import Iterator
    from logging import Logger

    from airflow.providers.google.cloud.hooks.bigquery import BigQueryHook


[docs]def bigquery_get_data( logger: Logger, dataset_id: str, table_id: str, big_query_hook: BigQueryHook, batch_size: int, selected_fields: list[str] | str | None, ) -> Iterator: logger.info("Fetching Data from:") logger.info("Dataset: %s ; Table: %s", dataset_id, table_id) for start_index in itertools.count(step=batch_size): rows: list[Row] | RowIterator = big_query_hook.list_rows( dataset_id=dataset_id, table_id=table_id, max_results=batch_size, selected_fields=selected_fields, start_index=start_index, ) if isinstance(rows, RowIterator): raise TypeError("BigQueryHook.list_rows() returns iterator when return_iterator=False (default)") if len(rows) == 0: logger.info("Job Finished") return logger.info("Total Extracted rows: %s", len(rows) + start_index) yield [row.values() for row in rows]

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