将数据加载到表配置单元中

Posted 2023-03-27

【中文标题】将数据加载到表配置单元中

【英文标题】：load data into table hive

【发布时间】：2015-01-05 15:56:32

【问题描述】：

我正在尝试配置 Hive 以使用 JDBC，我在 eclipse 上使用了这个示例：

public class HiveJdbcClient 
    private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";
    /**
    * @param args
    * @throws SQLException
    **/
    public static void main(String[] args) throws SQLException 
        try 
            Class.forName(driverName);
         catch (ClassNotFoundException e)
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.exit(1);
        
        Connection con = DriverManager.getConnection("jdbc:hive://localhost:10000/default", "", "");
        Statement stmt = con.createStatement();
        String tableName = "testHiveDriverTable";
        stmt.executeQuery("drop table " + tableName);
        ResultSet res = stmt.executeQuery("create table " + tableName + " (key int, value string)");

        // show tables
        String sql = "show tables '" + tableName + "'";
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        if (res.next()) 
            System.out.println(res.getString(1));
        

        // describe table
        sql = "describe " + tableName;
        System.out.println("Running: " + sql);  
        res = stmt.executeQuery(sql);
        while (res.next()) 
            System.out.println(res.getString(1) + "\t" + res.getString(2));
        

        // load data into table
        // NOTE: filepath has to be local to the hive server
        // NOTE: /tmp/test_hive_server.txt is a ctrl-A separated file with two fields per line
        String filepath = "/tmp/test_hive_server.txt";
        sql = "load data local inpath '" + filepath + "' into table " + tableName;
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        // select * query
        sql = "select * from " + tableName;
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        while (res.next())
            System.out.println(String.valueOf(res.getInt(1)) + "\t" + res.getString(2));
        
        // regular hive query
        sql = "select count(1) from " + tableName;
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        while (res.next())
            System.out.println(res.getString(1));
        
    

我能够在 hive 上创建表，但是当我尝试将数据加载到表中时出现错误。所以我的问题是我应该在“test_hive_server.txt”中添加什么来使其工作！因为我尝试了一切，每次都遇到同样的错误。 谢谢！

错误：

Exception in thread "main" java.sql.SQLException: org.apache.thrift.TApplicationException: Internal error processing execute
    at org.apache.hadoop.hive.jdbc.HiveStatement.executeQuery(HiveStatement.java:196)
    at com.palmyra.nosql.HiveJdbcClient.main(HiveJdbcClient.java:52)

【问题讨论】：

请同时发布错误信息。

您可以查看此链接***.com/a/31130602 以获取自动配置单元脚本生成工具。

【参考方案1】：

其实我自己找到了答案：

ROW FORMAT DELIMITED FIELDS TERMINATED BY ' ';

确定我们要加载到表中的“file.txt”中行的格式，Hive 的默认记录和字段分隔符列表是：

\n

^A

^B

^C

press ^V^A could insert a ^A in Vim.

或者你可以这样做： create table tableName (key int, value string) ROW FORMAT DELIMITED FIELDS TERMINATED BY ' ';

'file.txt' 应该是这样的：

value1 value2
value3 value4

在这个例子中 value1 和 value3 代表键 而value4和value5代表值