查询基于列的时间分区表

查询使用基于列的时间分区的表。

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"

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

// queryPartitionedTable demonstrates querying a time partitioned table and using a predicate that
// leverages the partitioned column.
func queryPartitionedTable(w io.Writer, projectID, datasetID, tableID string) error {
	// projectID := "my-project-id"
	// datasetID := "mydataset"
	// tableID := "mytable"
	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(fmt.Sprintf("SELECT * FROM `%s.%s` WHERE `date` BETWEEN DATE('1800-01-01') AND DATE('1899-12-31')", datasetID, tableID))
	// 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;

// Sample to run query on partitioned table.
public class QueryPartitionedTable {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";
    String query =
        String.format(
            "SELECT * FROM `%s.%s` WHERE date BETWEEN @start_date AND @end_date",
            datasetName, tableName);
    queryPartitionedTable(query);
  }

  public static void queryPartitionedTable(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();

      QueryJobConfiguration queryConfig =
          QueryJobConfiguration.newBuilder(query)
              .addNamedParameter("start_date", QueryParameterValue.date("1800-01-01"))
              .addNamedParameter("end_date", QueryParameterValue.date("1899-12-31"))
              .build();

      TableResult results = bigquery.query(queryConfig);

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

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

后续步骤

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