在JDBC中查询

要想通过JDBC代码的方式执行SQL查询，需要先执行hiveserver2命令。

> cd /home/work/hive-3.1.3
> ./bin/hiveserver2
......

创建Maven项目，引入依赖。

<dependency>
    <groupId>org.apache.hive</groupId>
    <artifactId>hive-jdbc</artifactId>
    <version>3.1.3</version>
    <exclusions>
        <exclusion>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
        </exclusion>
    </exclusions>
</dependency>

需要先在Hive中创建一张test表才能实现数据查询。

> cd /home/work/hive-3.1.3
> ./bin/beeline -u jdbc:hive2://172.16.185.176:10000 -n root
......
0: jdbc:hive2://172.16.185.176:10000> create table test(id int, name string);
......
INFO  : OK
INFO  : Concurrency mode is disabled, not creating a lock manager
No rows affected (1.809 seconds)

再插入测试数据。

0: jdbc:hive2://172.16.185.176:10000> insert into test(id, name) values(1, "lixingyun");
......
INFO  : OK
INFO  : Concurrency mode is disabled, not creating a lock manager
No rows affected (10.025 seconds)

0: jdbc:hive2://172.16.185.176:10000> select * from test;
......
+----------+------------+
| test.id  | test.name  |
+----------+------------+
| 1        | lixingyun  |
+----------+------------+
1 row selected (1.083 seconds)

开始编写实现代码。

package com.itechthink.hive;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 * 通过JDBC代码操作Hive
 * 需要先启动hiverserver2服务
 *
 */
public class HiveJdbcJob {
    public static void main(String[] args) throws Exception {
        // 指定hiveserver2链接
        String jdbcUrl = "jdbc:hive2://172.16.185.176:10000";
        // user使用root，password随便指定
        Connection conn = DriverManager.getConnection(jdbcUrl, "root", "any");
        // 获取Statement
        Statement stmt = conn.createStatement();
        // 指定查询的sql
        String sql = "select * from test";
        // 执行sql
        ResultSet res = stmt.executeQuery(sql);
        // 循环读取结果
        while (res.next()) {
            System.out.println(res.getInt("id") + "\t" + res.getString("name"));
        }
    }
}

---

感谢支持

更多内容，请移步《超级个体》。