Script di query

Esegui uno script di query.

Esempio di codice

Java

Prima di provare questo esempio, segui le istruzioni di configurazione Java nella guida rapida di BigQuery per l'utilizzo delle librerie client. Per saperne di più, consulta la documentazione di riferimento dell' API Java di BigQuery.

Per eseguire l'autenticazione in BigQuery, configura le Credenziali predefinite dell'applicazione. Per saperne di più, vedi Configura l'autenticazione per le librerie client.

import com.google.api.gax.paging.Page;
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 run query script.
public class QueryScript {

  public static void main(String[] args) {
    String script =
        "-- Declare a variable to hold names as an array.\n"
            + "DECLARE top_names ARRAY<STRING>;\n"
            + "-- Build an array of the top 100 names from the year 2017.\n"
            + "SET top_names = (\n"
            + "  SELECT ARRAY_AGG(name ORDER BY number DESC LIMIT 100)\n"
            + "  FROM `bigquery-public-data`.usa_names.usa_1910_current\n"
            + "  WHERE year = 2017\n"
            + ");\n"
            + "-- Which names appear as words in Shakespeare's plays?\n"
            + "SELECT\n"
            + "  name AS shakespeare_name\n"
            + "FROM UNNEST(top_names) AS name\n"
            + "WHERE name IN (\n"
            + "  SELECT word\n"
            + "  FROM `bigquery-public-data`.samples.shakespeare\n"
            + ");";
    queryScript(script);
  }

  public static void queryScript(String script) {
    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 queryConfig = QueryJobConfiguration.newBuilder(script).build();
      Job createJob = bigquery.create(JobInfo.of(queryConfig));
      // Wait for the whole script to finish.
      JobInfo jobInfo = createJob.waitFor();
      String parentJobId = jobInfo.getJobId().getJob();

      // Fetch jobs created by the SQL script.
      Page<Job> childJobs = bigquery.listJobs(BigQuery.JobListOption.parentJobId(parentJobId));
      childJobs
          .iterateAll()
          .forEach(job -> System.out.printf("Child Job Id: ", job.getJobId().getJob()));

      System.out.println("Query script performed successfully.");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Query not performed \n" + e.toString());
    }
  }
}

Rust

use google_cloud_bigquery::client::BigQuery;

pub async fn sample(project_id: &str) -> anyhow::Result<()> {
    let client = BigQuery::builder().build().await?;

    let mut rows = client
        .query(
            r#"
DECLARE target_state STRING DEFAULT 'TX';
SELECT name FROM `bigquery-public-data.usa_names.usa_1910_2013`
WHERE state = target_state
LIMIT 10;
"#,
        )
        .with_project_id(project_id)
        .set_location("US")
        .run()
        .await?
        .until_done()
        .await?
        .read();

    while let Some(row) = rows.next().await.transpose()? {
        let name: String = row.get("name");
        println!("Name: {name}");
    }
    Ok(())
}

Passaggi successivi

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