2018-10-29#regexp_extract+get_json

2018-10-29#regexp_extract+get_json_object

Hive/LanguageManual+UDF

正则表达式解析函数：regexp_extract

语法: regexp_extract(string subject, string pattern, int index)

返回值: string

说明：将字符串subject按照pattern正则表达式的规则拆分，返回index指定的字符。注意，在有些情况下要使用转义字符
举例：

hive> select regexp_extract(‘foothebar’, ‘foo(.*?)(bar)’, 1) from dual;
the

hive> select regexp_extract(‘foothebar’, ‘foo(.*?)(bar)’, 2) from dual;
bar

hive> select regexp_extract(‘foothebar’, ‘foo(.*?)(bar)’, 0) from dual;
foothebar

-- 最近遇到的一个例子
select regexp_extract('{"search_content": "bikerjacket","result_content": "2`bikerjacket`1","abtest": ""}', 'result_content": "(.*?)",', 0);

json串解析：get_json_object

select get_json_object('{"search_content": "bikerjacket","result_content": "2`bikerjacket`1","abtest": ""}', '$.result_content');

json array 串解析

待解析数据

[{"orderPromotionId":"order_149","orderPromotionTag":"日亚美妆专题-2件8折","orderPromotionType":"10","orderPromotionValue":"110.60"}]

json array string 解析

select get_json_object(regexp_extract('[{"orderPromotionId":"order_149","orderPromotionTag":"日亚美妆专题-2件8折","orderPromotionType":"10","orderPromotionValue":"110.60"}]','^\[(.+)\]$',1), '$.orderPromotionId');

行转列

参考示例：

SELECT get_json_object(single_json_table.single_json, '$.ts') AS ts,
get_json_object(single_json_table.single_json, '$.id') AS id,
get_json_object(single_json_table.single_json, '$.log') AS log
FROM (
    SELECT explode(json_array_col) as single_json FROM jt
    ) single_json_table ;

SELECT get_json_object(single_json_table.single_json, '$.orderPromotionId') AS ts,
get_json_object(single_json_table.single_json, '$.orderPromotionTag') AS id,
get_json_object(single_json_table.single_json, '$.orderPromotionType') AS log
FROM (
    SELECT explode('[{"orderPromotionId":"order_149","orderPromotionTag":"日亚美妆专题-2件8折","orderPromotionType":"10","orderPromotionValue":"110.60"}]') as single_json 
    -- FROM jt
    ) single_json_table ;

参考资料：csdn-hive中解析json数组