hadoop(十) - hive安装与自定义函数

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一. Hive安装

Hive只在一个节点上安装即可

3.1 配置HIVE_HOME环境变量

3.2 安装mysql

添加如下内容：

<property>
	  <name>javax.jdo.option.ConnectionURL</name>
	  <value>jdbc:mysql://hadoop00:3306/hive?createDatabaseIfNotExist=true</value>
	  <description>JDBC connect string for a JDBC metastore</description>
	</property>

	<property>
	  <name>javax.jdo.option.ConnectionDriverName</name>
	  <value>com.mysql.jdbc.Driver</value>
	  <description>Driver class name for a JDBC metastore</description>
	</property>

	<property>
	  <name>javax.jdo.option.ConnectionUserName</name>
	  <value>root</value>
	  <description>username to use against metastore database</description>
	</property>

	<property>
	  <name>javax.jdo.option.ConnectionPassword</name>
	  <value>123</value>
	  <description>password to use against metastore database</description>
	</property>

建分区表:

create table td_part(id bigint, account string, income double, expenses double, time string) partitioned by (logdate string) row format delimited fields terminated by ‘\t‘;

建外部表:

select nation, avg(size) from beauties group by nation order by avg(size);

二. UDF

自定义UDF要继承org.apache.hadoop.hive.ql.exec.UDF类实现evaluate 

public class AreaUDF extends UDF{

	private static Map<Integer, String> areaMap = new HashMap<Integer, String>();
	
	static {
		areaMap.put(1, "北京");
		areaMap.put(2, "上海");
		areaMap.put(3, "广州");
	}
	
	public Text evaluate(Text in){
		String result = areaMap.get(Integer.parseInt(in.toString()));
		if(result == null){
			result = "其他";
		}
		return new Text(result);
	}
}

hadoop(十) - hive安装与自定义函数

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原文地址：http://blog.csdn.net/zdp072/article/details/42197905