Hive lateral view ,get_json_object,json_tuple 用法

【Hive】解析json（get_json_object） https://blog.csdn.net/qq_34105362/article/details/80454697

lateral view：如果指定字段名则需要把lateral view查询出的列写到select中，才能在结果中出现；如果直接是select * 则自动会把lateral view查询出的列追加在后面。

select   *  from sales_info where dt = '2019-04-26'

----------------------------

select *, 
get_json_object(state, '$.id') as id, 
get_json_object(state, '$.token') as token, 
get_json_object(state, '$.user_name') as user_name
from sales_info where dt = '2019-04-26';

 ----------------------------

select *
from sales_info 
lateral view json_tuple(state,'id','token','user_name') state_json as id,token,user_name
where dt = '2019-04-26';

 ----------------------------

SELECT *
from
(select  *  from  sales_info  where dt = '2019-04-26') T1
lateral view json_tuple(state,'id','token','user_name') state_json as id,token,user_name

会自动把解析出的三个字段，添加到结果后面。