如何通过ODBC连接对BigQuery进行查询？

Question

能够通过ODBC使用BigQuery会很高兴.我已经通过ODBC使用了MySQL,这让我可以切换到BigQuery作为我的大数据表的MySQL的替代品.

Answer 1

Simba是ODBC的专家(他们几乎可以为你想到的每个数据源都有ODBC驱动程序),它为BigQuery构建了一个ODBC连接器.您可以从BigQuery的第三方工具页面,请免费下载(适用于Windows)这里(向下滚动到页面的底部).如果您更喜欢使用Linux,可以直接从此处下载Simba中的ODBC驱动程序.请注意,如果您从他们的网站下载,Simba会收取费用.他们的驱动程序可能更新,并将包括支持.

需要注意的一个功能是Simba驱动程序能够将标准的SQL-92兼容SQL转换为BigQUery的SQL方言.如果要将其用作关系数据库的替代品,这可能很有用.但是,如果要使用BigQuery的完整功能(嵌套数据,随机播放的JOIN/GROUP BY),则应关闭此开关以直接发送查询.

一旦安装了BigQuery ODBC驱动程序并创建了DSN(请参阅Simba ODBC文档以获取DSN创建的分步指南),您将需要开始进行ODBC查询.这是一个从C#执行此操作的代码示例.如果您编译并运行它,它将连接到BigQuery,运行一个简单的查询,并打印结果.

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Odbc;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BigQueryE2E
{
  /** 
   * Helper class to build an ODBC Connection to connect to a Simba 
   * BigQuery ODBC Driver.
   */
  class ConnectionBuilder {
    private String Dsn;
    private String Catalog;
    private String ExecCatalog;
    private bool UseNativeQuery;

    public ConnectionBuilder SetDsn(String dsn) { 
      Dsn = dsn; 
      return this; 
    }
    public ConnectionBuilder SetCatalog(String catalog) {
      Catalog = catalog; 
      return this; 
    }
    public ConnectionBuilder SetBillingCatalog(String catalog) {
      ExecCatalog = catalog;
      return this;
    }
    public ConnectionBuilder SetUseNativeQuery(bool nativeQuery) {
      UseNativeQuery = nativeQuery;
      return this;
    }

    public OdbcConnection Build() {
      if (Catalog == null || Dsn == null) {
        throw new ArgumentException("Missing required Connection setting");
      }

      StringBuilder connectionString = new StringBuilder();

      connectionString.AppendFormat("DSN={0}; Catalog={1};", Dsn, Catalog);
      if (ExecCatalog != null) {
        connectionString.AppendFormat("ExecCatalog={0};", ExecCatalog);
      }
      if (UseNativeQuery) {
        connectionString.Append("UseNativeQuery=1");
      }

      OdbcConnection conn = new OdbcConnection();
      conn.ConnectionString = connectionString.ToString();
      return conn;
    }
  }

  class Program {
    private static String Query = 
        "SELECT corpus, SUM(word_count) " + 
        "FROM samples.shakespeare " +
        "GROUP BY corpus";

    private static void PrintResults(OdbcDataReader reader) {
      for (int ii = 0; ii < reader.FieldCount; ii += 1) {
        System.Console.Write("{0}{1}",
            reader.GetName(ii),
            ii + 1 < reader.FieldCount ? "\t" : "\n");
      }
      while (reader.Read()) {
        for (int ii = 0; ii < reader.FieldCount; ii += 1) {
          System.Console.Write("{0}{1}",
              reader.GetValue(ii),
              ii + 1 < reader.FieldCount ? "\t" : "\n");
        }
      }
    }
    static void Main(string[] args) {
      OdbcConnection connection = new ConnectionBuilder()
          .SetDsn("bigquery1")
          .SetCatalog("publicdata")
          .SetBillingCatalog("bigquery-e2e")
          .Build();
      try {
        connection.Open();
        using (OdbcCommand command =  connection.CreateCommand()) {
          command.CommandText = Query;
          using (OdbcDataReader reader = command.ExecuteReader()) {
            PrintResults(reader);
          }
        }
      } catch (Exception ex) {
        System.Console.WriteLine("Error {0}: {1}",
          connection.State != ConnectionState.Open 
              ? "opening connection" : "executing query",
          ex);
      } finally {
        connection.Close();
      }
      System.Console.ReadKey();
    }
  }
}