运行查询并获取总行数

运行查询并从查询获取总行数。

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.QueryJobConfiguration;
import com.google.cloud.bigquery.TableResult;

// Sample to run query total rows
public class QueryTotalRows {

  public static void main(String[] args) {
    String query =
        "SELECT name FROM `bigquery-public-data.usa_names.usa_1910_2013`"
            + " WHERE state = \"TX\""
            + " LIMIT 100";
    queryTotalRows(query);
  }

  public static void queryTotalRows(String query) {
    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();

      TableResult results = bigquery.query(QueryJobConfiguration.of(query));

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

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
# client = bigquery.Client()

query = (
    "SELECT name FROM `bigquery-public-data.usa_names.usa_1910_2013` "
    'WHERE state = "TX" '
    "LIMIT 100"
)
results = client.query_and_wait(
    query,
    # Location must match that of the dataset(s) referenced in the query.
    location="US",
)  # API request - starts the query and waits for results.

print("Got {} rows.".format(results.total_rows))

后续步骤

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