时间戳参数

使用时间戳参数运行查询。

深入探索

如需查看包含此代码示例的详细文档，请参阅以下内容：

• 运行参数化查询

代码示例

C#

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

using Google.Cloud.BigQuery.V2;
using System;

public class BigQueryQueryWithTimestampParameters
{
    public void QueryWithTimestampParameters(string projectId = "project-id")
    {
        var timestamp = new DateTime(2016, 12, 7, 8, 0, 0, DateTimeKind.Utc);

        // Note: Standard SQL is required to use query parameters.
        var query = "SELECT TIMESTAMP_ADD(@ts_value, INTERVAL 1 HOUR);";

        // Initialize client that will be used to send requests.
        var client = BigQueryClient.Create(projectId);

        var parameters = new BigQueryParameter[]
        {
            new BigQueryParameter("ts_value", BigQueryDbType.Timestamp, timestamp),
        };

        var job = client.CreateQueryJob(
            sql: query,
            parameters: parameters,
            options: new QueryOptions { UseQueryCache = false });
        // Wait for the job to complete.
        job = job.PollUntilCompleted().ThrowOnAnyError();
        // Display the results
        foreach (BigQueryRow row in client.GetQueryResults(job.Reference))
        {
            Console.WriteLine(row[0]);
        }
    }
}

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，请设置应用默认凭据。 如需了解详情，请参阅为客户端库设置身份验证。

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/bigquery"
	"google.golang.org/api/iterator"
)

// queryWithTimestampParam demonstrates issuing a query and supplying a timestamp query parameter.
func queryWithTimestampParam(w io.Writer, projectID string) error {
	// projectID := "my-project-id"
	ctx := context.Background()
	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %w", err)
	}
	defer client.Close()

	q := client.Query(
		`SELECT TIMESTAMP_ADD(@ts_value, INTERVAL 1 HOUR);`)
	q.Parameters = []bigquery.QueryParameter{
		{
			Name:  "ts_value",
			Value: time.Date(2016, 12, 7, 8, 0, 0, 0, time.UTC),
		},
	}
	// Run the query and process the returned row iterator.
	it, err := q.Read(ctx)
	if err != nil {
		return fmt.Errorf("query.Read(): %w", err)
	}
	for {
		var row []bigquery.Value
		err := it.Next(&row)
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		fmt.Fprintln(w, row)
	}
	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.TableResult;
import org.threeten.bp.LocalDateTime;
import org.threeten.bp.ZoneOffset;
import org.threeten.bp.ZonedDateTime;

// Sample to running a query with timestamp query parameters.
public class QueryWithTimestampParameters {

  public static void main(String[] args) {
    queryWithTimestampParameters();
  }

  public static void queryWithTimestampParameters() {
    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();

      ZonedDateTime timestamp = LocalDateTime.of(2016, 12, 7, 8, 0, 0).atZone(ZoneOffset.UTC);
      String query = "SELECT TIMESTAMP_ADD(@ts_value, INTERVAL 1 HOUR);";
      // Note: Standard SQL is required to use query parameters.
      QueryJobConfiguration queryConfig =
          QueryJobConfiguration.newBuilder(query)
              .addNamedParameter(
                  "ts_value",
                  QueryParameterValue.timestamp(
                      // Timestamp takes microseconds since 1970-01-01T00:00:00 UTC
                      timestamp.toInstant().toEpochMilli() * 1000))
              .build();

      TableResult results = bigquery.query(queryConfig);

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

      System.out.println("Query with timestamp parameter 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。

// Run a query using timestamp parameters

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

async function queryParamsTimestamps() {
  // The SQL query to run
  const sqlQuery = 'SELECT TIMESTAMP_ADD(@ts_value, INTERVAL 1 HOUR);';

  const options = {
    query: sqlQuery,
    // Location must match that of the dataset(s) referenced in the query.
    location: 'US',
    params: {ts_value: new Date()},
  };

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

  console.log('Rows:');
  rows.forEach(row => console.log(row.f0_));
}

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，请设置应用默认凭据。 如需了解详情，请参阅为客户端库设置身份验证。

import datetime

from google.cloud import bigquery

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

query = "SELECT TIMESTAMP_ADD(@ts_value, INTERVAL 1 HOUR);"
job_config = bigquery.QueryJobConfig(
    query_parameters=[
        bigquery.ScalarQueryParameter(
            "ts_value",
            "TIMESTAMP",
            datetime.datetime(2016, 12, 7, 8, 0, tzinfo=datetime.timezone.utc),
        )
    ]
)
results = client.query_and_wait(
    query, job_config=job_config
)  # Make an API request.

for row in results:
    print(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。