hadoop - Hive ql Driver如何指定默认以外的数据库名称

Question

我正在编写一个示例程序，使用 org.apache.hadoop.hive.ql.Driver 类连接到 Hive Metastore。示例片段如下

String userName = "test";
HiveConf conf = new HiveConf(SessionState.class);
  conf.set("fs.default.name", "hdfs://" + hadoopMasterHost + ":8020"); 
  conf.set("hive.metastore.local","false");
  conf.set("hive.metastore.warehouse.dir","/user/hive/warehouse"); 
  conf.set("hive.metastore.uris","thrift://" + hadoopMasterHost + ":9083"); 
  conf.set("hadoop.bin.path", "/usr/hdp/2.2.0.0-2041/hadoop/bin"); 
  conf.set("yarn.nodemanager.hostname", hadoopMasterHost);
  conf.set("yarn.resourcemanager.hostname", hadoopMasterHost);

  ss = new MyCliSessionState(conf);
  ss.out = new PrintStream(System.out, true, "UTF-8");
  ss.err = new PrintStream(System.err, true, "UTF-8");

  SessionState.start(ss);

  driver = new Driver(conf);
  query = "show tables";

if (userName == null || userName.isEmpty())
        return driver.run(query);

    UserGroupInformation ugi = createUgi(userName);
    CommandProcessorResponse response = ugi.doAs(new PrivilegedExceptionAction<CommandProcessorResponse>() {
        public CommandProcessorResponse run() throws Exception {
            CliSessionState ss = null;
            ss = new MyCliSessionState(conf);
            ss.out = new PrintStream(System.out, true, "UTF-8");
            ss.err = new PrintStream(System.err, true, "UTF-8");

            // refresh thread local SessionState and Hive
            SessionState.start(ss);
            Hive.get(conf, true);

            return driver.run(query);
        }
    });

    return response;

我能够连接到默认 数据库并获取所有表的列表。但是我怎样才能连接到其他数据库(default 除外)？我尝试搜索配置单元配置属性，但找不到指定数据库名称的配置属性。有人可以帮帮我吗。

Answer 1

看起来您想以困难的方式做事，并重新实现 Beeline 实用程序。对于大多数人来说，这似乎是一种受虐狂的尝试，但我有什么资格评判呢？

无论如何，在这一点上你必须执行HQL命令，就像其他人一样......并且任何人都应该知道“使用”命令:

driver.run("use " +argDatabase) ;
// check status
driver.run("show tables") ;
// check status, parse output
driver.run("describe extended " +argTable) ;
// check status, parse output