定位参数和提供的类型

使用定位参数和提供的参数类型运行查询。

代码示例

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，请设置应用默认凭据。 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.QueryJobConfiguration;
import com.google.cloud.bigquery.QueryParameterValue;
import com.google.cloud.bigquery.StandardSQLTypeName;
import com.google.cloud.bigquery.TableResult;

// Sample to run query with positional types parameters.
public class QueryWithPositionalTypesParameters {

  public static void main(String[] args) {
    String[] words = {"and", "is", "the", "moon"};
    String corpus = "romeoandjuliet";
    Integer wordsCount = 250;
    String query =
        "SELECT word, word_count"
            + " FROM `bigquery-public-data.samples.shakespeare`"
            + " WHERE word IN UNNEST(?)"
            + " AND corpus = ?"
            + " AND word_count >= ?"
            + " ORDER BY word_count DESC";
    queryWithPositionalTypesParameters(query, words, corpus, wordsCount);
  }

  public static void queryWithPositionalTypesParameters(
      String query, String[] words, String corpus, Integer wordsCount) {
    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();

      QueryParameterValue wordList = QueryParameterValue.array(words, StandardSQLTypeName.STRING);
      QueryParameterValue corpusParam = QueryParameterValue.of(corpus, StandardSQLTypeName.STRING);
      QueryParameterValue minWordCount =
          QueryParameterValue.of(wordsCount, StandardSQLTypeName.INT64);

      // Note: Standard SQL is required to use query parameters.
      QueryJobConfiguration queryConfig =
          QueryJobConfiguration.newBuilder(query)
              .addPositionalParameter(wordList)
              .addPositionalParameter(corpusParam)
              .addPositionalParameter(minWordCount)
              .build();

      TableResult results = bigquery.query(queryConfig);

      results
          .iterateAll()
          .forEach(row -> row.forEach(val -> System.out.printf("%s,", val.toString())));

      System.out.println("Query with positional types parameters performed successfully.");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Query not performed \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，请设置应用默认凭据。 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
const {BigQuery} = require('@google-cloud/bigquery');
const bigquery = new BigQuery();

async function queryParamsPositionalTypes() {
  // Run a query using positional query parameters and provided parameter types.

  // The SQL query to run
  const sqlQuery = `SELECT word, word_count
  FROM \`bigquery-public-data.samples.shakespeare\`
  WHERE word IN UNNEST(?)
  AND corpus = ?
  AND word_count >= ?
  ORDER BY word_count DESC`;

  const queryOptions = {
    query: sqlQuery,
    params: [['and', 'is', 'the', 'moon'], 'romeoandjuliet', 250],
    types: [['STRING'], 'STRING', 'INT64'],
  };

  // Run the query
  const [rows] = await bigquery.query(queryOptions);

  console.log('Rows:');
  rows.forEach(row => console.log(row));
}

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。