使用 DDL 创建例程

使用 DDL 查询创建例程。

代码示例

Go

试用此示例之前，请按照 BigQuery 快速入门：使用客户端库中的 Go 设置说明进行操作。 如需了解详情，请参阅 BigQuery Go API 参考文档。

如需向 BigQuery 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为客户端库设置身份验证。

import (
	"context"
	"fmt"

	"cloud.google.com/go/bigquery"
)

// createRoutineDDL demonstrates creating a new BigQuery UDF using a DDL query.
func createRoutineDDL(projectID, datasetID, routineID string) error {
	// projectID := "my-project-id"
	// datasetID := "mydatasetid"
	// routineID := "myroutineid"
	ctx := context.Background()

	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %w", err)
	}
	defer client.Close()

	routineName, err := client.Dataset(datasetID).Routine(routineID).Identifier(bigquery.StandardSQLID)
	if err != nil {
		return fmt.Errorf("couldn't generate identifier: %w", err)
	}

	sql := fmt.Sprintf(`CREATE FUNCTION %s(
        	arr ARRAY<STRUCT<name STRING, val INT64>>
    		) AS (
        	(SELECT SUM(IF(elem.name = "foo",elem.val,null)) FROM UNNEST(arr) AS elem)
    		)`, routineName)

	job, err := client.Query(sql).Run(ctx)
	if err != nil {
		return err
	}
	status, err := job.Wait(ctx)
	if err != nil {
		return err
	}
	if err := status.Err(); err != nil {
		return err
	}
	return nil
}

Java

试用此示例之前，请按照 BigQuery 快速入门：使用客户端库中的 Java 设置说明进行操作。 如需了解详情，请参阅 BigQuery Java API 参考文档。

如需向 BigQuery 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为客户端库设置身份验证。

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobInfo;
import com.google.cloud.bigquery.QueryJobConfiguration;

// Sample to create a routine using DDL
public class CreateRoutineDdl {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "MY_PROJECT_ID";
    String datasetId = "MY_DATASET_ID";
    String routineId = "MY_ROUTINE_ID";
    String sql =
        "CREATE FUNCTION "
            + "`"
            + projectId
            + "."
            + datasetId
            + "."
            + routineId
            + "`"
            + "( arr ARRAY<STRUCT<name STRING, val INT64>>) AS "
            + "( (SELECT SUM(IF(elem.name = \"foo\",elem.val,null)) FROM UNNEST(arr) AS elem))";
    createRoutineDdl(sql);
  }

  public static void createRoutineDdl(String sql) {
    try {
      // Initialize client that will be used to send requests. This client only needs to be created
      // once, and can be reused for multiple requests.
      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

      QueryJobConfiguration config = QueryJobConfiguration.newBuilder(sql).build();

      // create a routine using query and it will wait to complete job.
      Job job = bigquery.create(JobInfo.of(config));
      job = job.waitFor();
      if (job.isDone()) {
        System.out.println("Routine created successfully");
      } else {
        System.out.println("Routine was not created");
      }
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Routine was not created. \n" + e.toString());
    }
  }
}

Node.js

试用此示例之前，请按照 BigQuery 快速入门：使用客户端库中的 Node.js 设置说明进行操作。 如需了解详情，请参阅 BigQuery Node.js API 参考文档。

如需向 BigQuery 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为客户端库设置身份验证。

// Import the Google Cloud client library and create a client
const {BigQuery} = require('@google-cloud/bigquery');
const bigquery = new BigQuery();

async function createRoutineDDL() {
  // Creates a routine using DDL.

  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // projectId = 'my_project';
  // const datasetId = 'my_dataset';
  // const routineId = 'my_routine';

  const query = `CREATE FUNCTION \`${projectId}.${datasetId}.${routineId}\`(
      arr ARRAY<STRUCT<name STRING, val INT64>>
  ) AS (
      (SELECT SUM(IF(elem.name = "foo",elem.val,null)) FROM UNNEST(arr) AS elem)
  )`;

  const options = {
    query: query,
  };

  // Run the query as a job
  const [job] = await bigquery.createQueryJob(options);
  console.log(`Job ${job.id} started.`);

  // Wait for the query to finish
  await job.getQueryResults();

  console.log(`Routine ${routineId} created.`);
}
createRoutineDDL();

Python

试用此示例之前，请按照 BigQuery 快速入门：使用客户端库中的 Python 设置说明进行操作。 如需了解详情，请参阅 BigQuery Python API 参考文档。

如需向 BigQuery 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为客户端库设置身份验证。

from google.cloud import bigquery

# Construct a BigQuery client object.
client = bigquery.Client()

# TODO(developer): Choose a fully-qualified ID for the routine.
# routine_id = "my-project.my_dataset.my_routine"

sql = """
CREATE FUNCTION `{}`(
    arr ARRAY<STRUCT<name STRING, val INT64>>
) AS (
    (SELECT SUM(IF(elem.name = "foo",elem.val,null)) FROM UNNEST(arr) AS elem)
)
""".format(
    routine_id
)
query_job = client.query(sql)  # Make an API request.
query_job.result()  # Wait for the job to complete.

print("Created routine {}".format(query_job.ddl_target_routine))

后续步骤

如需搜索和过滤其他 Google Cloud 产品的代码示例，请参阅Google Cloud 示例浏览器。