DML로 테이블 업데이트

DML 쿼리를 사용하여 BigQuery 테이블의 데이터를 업데이트합니다.

코드 샘플

Java

이 샘플을 사용해 보기 전에 BigQuery 빠른 시작: 클라이언트 라이브러리 사용의 Java 설정 안내를 따르세요. 자세한 내용은 BigQuery Java API 참고 문서를 확인하세요.

BigQuery에 인증하려면 애플리케이션 기본 사용자 인증 정보를 설정합니다. 자세한 내용은 클라이언트 라이브러리의 인증 설정을 참조하세요.

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.FormatOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobId;
import com.google.cloud.bigquery.QueryJobConfiguration;
import com.google.cloud.bigquery.TableDataWriteChannel;
import com.google.cloud.bigquery.TableId;
import com.google.cloud.bigquery.TableResult;
import com.google.cloud.bigquery.WriteChannelConfiguration;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.channels.Channels;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.UUID;

// Sample to update data in BigQuery tables using DML query
public class UpdateTableDml {

  public static void main(String[] args) throws IOException, InterruptedException {
    // TODO(developer): Replace these variables before running the sample.
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";
    updateTableDml(datasetName, tableName);
  }

  public static void updateTableDml(String datasetName, String tableName)
      throws IOException, InterruptedException {
    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();

      // Load JSON file into UserSessions table
      TableId tableId = TableId.of(datasetName, tableName);

      WriteChannelConfiguration writeChannelConfiguration =
          WriteChannelConfiguration.newBuilder(tableId)
              .setFormatOptions(FormatOptions.json())
              .build();

      // Imports a local JSON file into a table.
      Path jsonPath =
          FileSystems.getDefault().getPath("src/test/resources", "userSessionsData.json");

      // The location and JobName must be specified; other fields can be auto-detected.
      String jobName = "jobId_" + UUID.randomUUID().toString();
      JobId jobId = JobId.newBuilder().setLocation("us").setJob(jobName).build();

      try (TableDataWriteChannel writer = bigquery.writer(jobId, writeChannelConfiguration);
          OutputStream stream = Channels.newOutputStream(writer)) {
        Files.copy(jsonPath, stream);
      }

      // Get the Job created by the TableDataWriteChannel and wait for it to complete.
      Job job = bigquery.getJob(jobId);
      Job completedJob = job.waitFor();
      if (completedJob == null) {
        System.out.println("Job not executed since it no longer exists.");
        return;
      } else if (completedJob.getStatus().getError() != null) {
        System.out.println(
            "BigQuery was unable to load local file to the table due to an error: \n"
                + job.getStatus().getError());
        return;
      }

      System.out.println(
          job.getStatistics().toString() + " userSessionsData json uploaded successfully");

      // Write a DML query to modify UserSessions table
      // To create DML query job to mask the last octet in every row's ip_address column
      String dmlQuery =
          String.format(
              "UPDATE `%s.%s` \n"
                  + "SET ip_address = REGEXP_REPLACE(ip_address, r\"(\\.[0-9]+)$\", \".0\")\n"
                  + "WHERE TRUE",
              datasetName, tableName);

      QueryJobConfiguration dmlQueryConfig = QueryJobConfiguration.newBuilder(dmlQuery).build();

      // Execute the query.
      TableResult result = bigquery.query(dmlQueryConfig);

      // Print the results.
      result.iterateAll().forEach(rows -> rows.forEach(row -> System.out.println(row.getValue())));

      System.out.println("Table updated successfully using DML");
    } catch (BigQueryException e) {
      System.out.println("Table update failed \n" + e.toString());
    }
  }
}

Python

이 샘플을 사용해 보기 전에 BigQuery 빠른 시작: 클라이언트 라이브러리 사용의 Python 설정 안내를 따르세요. 자세한 내용은 BigQuery Python API 참고 문서를 확인하세요.

BigQuery에 인증하려면 애플리케이션 기본 사용자 인증 정보를 설정합니다. 자세한 내용은 클라이언트 라이브러리의 인증 설정을 참조하세요.

import pathlib
from typing import Dict, Optional

from google.cloud import bigquery
from google.cloud.bigquery import enums


def load_from_newline_delimited_json(
    client: bigquery.Client,
    filepath: pathlib.Path,
    project_id: str,
    dataset_id: str,
    table_id: str,
) -> None:
    full_table_id = f"{project_id}.{dataset_id}.{table_id}"
    job_config = bigquery.LoadJobConfig()
    job_config.source_format = enums.SourceFormat.NEWLINE_DELIMITED_JSON
    job_config.schema = [
        bigquery.SchemaField("id", enums.SqlTypeNames.STRING),
        bigquery.SchemaField("user_id", enums.SqlTypeNames.INTEGER),
        bigquery.SchemaField("login_time", enums.SqlTypeNames.TIMESTAMP),
        bigquery.SchemaField("logout_time", enums.SqlTypeNames.TIMESTAMP),
        bigquery.SchemaField("ip_address", enums.SqlTypeNames.STRING),
    ]

    with open(filepath, "rb") as json_file:
        load_job = client.load_table_from_file(
            json_file, full_table_id, job_config=job_config
        )

    # Wait for load job to finish.
    load_job.result()


def update_with_dml(
    client: bigquery.Client, project_id: str, dataset_id: str, table_id: str
) -> int:
    query_text = f"""
    UPDATE `{project_id}.{dataset_id}.{table_id}`
    SET ip_address = REGEXP_REPLACE(ip_address, r"(\\.[0-9]+)$", ".0")
    WHERE TRUE
    """
    query_job = client.query(query_text)

    # Wait for query job to finish.
    query_job.result()

    assert query_job.num_dml_affected_rows is not None

    print(f"DML query modified {query_job.num_dml_affected_rows} rows.")
    return query_job.num_dml_affected_rows


def run_sample(override_values: Optional[Dict[str, str]] = None) -> int:
    if override_values is None:
        override_values = {}

    client = bigquery.Client()
    filepath = pathlib.Path(__file__).parent / "user_sessions_data.json"
    project_id = client.project
    dataset_id = "sample_db"
    table_id = "UserSessions"
    load_from_newline_delimited_json(client, filepath, project_id, dataset_id, table_id)
    return update_with_dml(client, project_id, dataset_id, table_id)

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