feat(bigquery): add bigquery_create_procedure sample to create a SQL stored procedure

Problem:
The BigQuery documentation (https://cloud.google.com/bigquery/docs/procedures)
needs a standalone, tested Python code sample demonstrating how to
create a SQL stored procedure (region tag `bigquery_create_procedure`).

Solution:
- Add `create_procedure(project_id: str, dataset_id: str) -> None` in `bigquery/stored_procedures/bigquery_create_procedure.py`
  (Create a reusable multi-statement GoogleSQL stored procedure inside a BigQuery dataset using CREATE OR REPLACE PROCEDURE.)
- Add unit tests (`bigquery/stored_procedures/bigquery_create_procedure_test.py`) covering both the success
  path and API error handling (`GoogleAPICallError`)

Author: iennae

bigquery/stored_procedures/bigquery_create_procedure.py

@@ -0,0 +1,78 @@
+# Copyright 2026 Google LLC
+#
+# Licensed 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
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START bigquery_create_procedure]
+import sys
+
+from google.api_core import exceptions
+from google.cloud import bigquery
+
+
+def create_procedure(
+    project_id: str,
+    dataset_id: str,
+) -> None:
+    """Creates a GoogleSQL stored procedure in a BigQuery dataset.
+
+    Args:
+        project_id: Google Cloud project ID (for example, 'example-project').
+        dataset_id: BigQuery dataset ID where the procedure is created
+            (for example, 'example_dataset').
+    """
+    client = bigquery.Client(project=project_id)
+    # Use a fixed procedure identifier inside the caller-supplied dataset.
+    # The procedure body queries the public Shakespeare dataset in bigquery-public-data
+    # (https://cloud.google.com/bigquery/public-data).
+    procedure_id = "example_procedure"
+    routine_ref = f"{project_id}.{dataset_id}.{procedure_id}"
+    sql = f"""
+        CREATE OR REPLACE PROCEDURE `{routine_ref}`(
+          target_corpus STRING,
+          OUT total_words INT64
+        )
+        BEGIN
+          SET total_words = (
+            SELECT COALESCE(SUM(word_count), 0)
+            FROM `bigquery-public-data.samples.shakespeare`
+            WHERE corpus = target_corpus
+          );
+        END;
+    """
+
+    try:
+        print(f"Creating stored procedure: {routine_ref}")
+        query_job = client.query(sql)
+        query_job.result()
+    except exceptions.NotFound as err:
+        print(
+            f"error: dataset '{dataset_id}' not found in project '{project_id}' "
+            f"when creating stored procedure '{procedure_id}': {err.message}",
+            file=sys.stderr,
+        )
+        return
+    except exceptions.GoogleAPICallError as err:
+        print(
+            f"error: failed to create stored procedure '{procedure_id}' in dataset "
+            f"'{dataset_id}' for project '{project_id}': {err.message}",
+            file=sys.stderr,
+        )
+        return
+
+    print(f"Resource ID: {routine_ref}")
+    print(f"Job ID: {query_job.job_id}")
+    print(f"Procedure ID: {procedure_id}")
+    print(f"Statement Type: {query_job.statement_type}")
+
+
+# [END bigquery_create_procedure]

bigquery/stored_procedures/bigquery_create_procedure_test.py

@@ -0,0 +1,70 @@
+# Copyright 2026 Google LLC
+#
+# Licensed 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
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest import mock
+
+import bigquery_create_procedure
+from google.api_core import exceptions
+import pytest
+
+
+def test_create_procedure_success(
+    monkeypatch: pytest.MonkeyPatch,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    mock_client = mock.MagicMock()
+    mock_job = mock.MagicMock()
+    mock_job.job_id = "example-job-123"
+    mock_job.statement_type = "SCRIPT"
+    mock_job.result.return_value = []
+    mock_client.query.return_value = mock_job
+    monkeypatch.setattr(
+        bigquery_create_procedure.bigquery,
+        "Client",
+        lambda project=None: mock_client,
+    )
+
+    bigquery_create_procedure.create_procedure(
+        project_id="example-project",
+        dataset_id="example_dataset",
+    )
+
+    captured = capsys.readouterr()
+    assert "Resource ID:" in captured.out
+    assert "example-project" in captured.out
+    assert mock_client.query.called
+
+
+def test_create_procedure_error(
+    monkeypatch: pytest.MonkeyPatch,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    mock_client = mock.MagicMock()
+    mock_job = mock.MagicMock()
+    mock_job.result.side_effect = exceptions.NotFound("resource error")
+    mock_client.query.return_value = mock_job
+    monkeypatch.setattr(
+        bigquery_create_procedure.bigquery,
+        "Client",
+        lambda project=None: mock_client,
+    )
+
+    bigquery_create_procedure.create_procedure(
+        project_id="example-project",
+        dataset_id="example_dataset",
+    )
+
+    captured = capsys.readouterr()
+    assert "error:" in captured.err
+    assert "example-project" in captured.err

bigquery/stored_procedures/noxfile_config.py

@@ -0,0 +1,23 @@
+# Copyright 2026 Google LLC
+#
+# Licensed 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
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+TEST_CONFIG_OVERRIDE = {
+    # You can opt out from the test for specific Python versions.
+    "ignored_versions": ["2.7", "3.7", "3.8", "3.9", "3.10", "3.11"],
+    # Enforce type hints on new samples.
+    "enforce_type_hints": True,
+    "gcloud_project_env": "GOOGLE_CLOUD_PROJECT",
+    "pip_version_override": None,
+    "envs": {},
+}

bigquery/stored_procedures/requirements-test.txt

@@ -0,0 +1 @@
+pytest==9.0.3; python_version >= "3.10"

bigquery/stored_procedures/requirements.txt

@@ -0,0 +1 @@
+google-cloud-bigquery==3.47.0