当Hive提供的内置函数无法满足你的业务处理需要时,此时就可以考虑使用用户自定义函数(UDF:user-defined function) 根据用户自定义函数类别分为以下三种: UDF(User-Defined-Function) 一进一出 UDAF(User-Defined Aggregation Function) 聚集函数,多进一出,类似于:count/max/min
SELECT json_array_get('["a", [3, 9], "c"]', 1); -- JSON '[3,9]' 1. 2. This function also supports negative indexes for fetching element indexed from the end of an array: SELECT json_array_get('["c", [3, 9], "a"]', -1); -- JSON 'a' (invalid JSON) SELECT json...
第一个参数:指定要解析的JSON字符串 第二个参数:指定要返回的字段,通过$.columnName的方式来指定path 特点:每次只能返回JSON对象中一列的值 使用 创建表 -- 切换数据库 use db_function; -- 创建表 create table tb_json_test1 ( json string ); 加载数据 -- 加载数据 load data local inpath '/ex...
It will return null if the input json string is invalid. 「NOTE: The json path can only have the characters [0-9a-z_], i.e., no upper-case or special characters. Also, the keys *cannot start with numbers.」* This is due to restrictions on Hive column names..「从指定路径上的 ...
SELECT customer_name, explode( from_json( cars_rented, 'ARRAY<STRUCT<car_model:STRING, price:INT, rental_days:INT>>' ) ).car_model AS car_model FROM customer_tranx; -- Output: error: SemanticException [Error 10011]: Line 2:5 Invalid function explode in select clause 报错了,这错误一般人...
echo Invalid Args! echo 'Usage: '$(basename $0)' start|stop|restart|status' ;; esac ./hiveserver2.sh start hiveserver2 启动有点慢一般要等几分钟,多运行几次./hiveserver2.sh status就会出现正常了 使用客户端工具连接 第一阶段结束了好好休息下,希望能完成下面的所有阶段一定会有提升...
0: jdbc:hive2://hadoop01:10000/hivesql> create function explodeJsonArray as "com.tiantianfund.udf.GetJsonArray" using jar 'hdfs://hadoop01:8020/user/hive/lib1/uft-1.0-SNAPSHOT.jar'; No rows affected (0.087 seconds) 第十一、查看函数 ...
It will return null if the input json string is invalid. NOTE: The json path can only have the characters [0-9a-z_], i.e., no upper-case or special characters. Also, the keys cannot start with numbers. * This is due to restrictions on Hive column names..从指定路径上的JSON字符串...
Apache Hive 是一个基于 Hadoop 分布式文件系统 (HDFS) 的数据仓库软件项目,专为存储和处理大规模数据集而设计。它提供类似 SQL 的查询语言 HiveQL,使用户...
It will return null if the input json string is invalid. NOTE: The json path can only have the characters [0-9a-z_], i.e., no upper-case or special characters. Also, the keys *cannot start with numbers.* This is due to restrictions on Hive column names.. 从指定路径上的JSON字符...