Can we flatten column which contain Json as value in Hive table?

Question

I have one hive column 'events' with Json values.How can i flatten this Json to create one hive table with columns as the key field of Json.Is it even possible? ex- I need hive table columns to be events,start_date,id,details with corresponding values.

| events |

|[{"start_date":20201230,"id":"3245ret","details":"Imp"},{"start_date":20201228,"id":"3245rtr","details":"NoImp"}] |

|[{"start_date":20191230,"id":"3245ret","details":"vImp"},{"start_date":20191228,"id":"3245rwer","details":"NoImp"}]|

Answer 1

Demo:

select events, 
get_json_object(element,'$.id') as id,
get_json_object(element,'$.start_date') as start_date,
get_json_object(element,'$.details') as details
from
(
select '[{"start_date":20201230,"id":"3245ret","details":"Imp"},{"start_date":20201228,"id":"3245rtr","details":"NoImp"}]' as events
union all 
select '[{"start_date":20191230,"id":"3245ret","details":"vImp"},{"start_date":20191228,"id":"3245rwer","details":"NoImp"}]' as events
) s lateral view outer explode (split(regexp_replace(events, '\\[|\\]',''),'(?<=\\}),(?=\\{)')) e as element

Initial string is splitted by comma between curly brackets, ( see explanation here ), array exploded with lateral view and JSON objects parsed using get_json_object

Result:

 events                                                                                                             id       start_date details
[{"start_date":20201230,"id":"3245ret","details":"Imp"},{"start_date":20201228,"id":"3245rtr","details":"NoImp"}]   3245ret  20201230  Imp
[{"start_date":20201230,"id":"3245ret","details":"Imp"},{"start_date":20201228,"id":"3245rtr","details":"NoImp"}]   3245rtr  20201228  NoImp
[{"start_date":20191230,"id":"3245ret","details":"vImp"},{"start_date":20191228,"id":"3245rwer","details":"NoImp"}] 3245ret  20191230  vImp
[{"start_date":20191230,"id":"3245ret","details":"vImp"},{"start_date":20191228,"id":"3245rwer","details":"NoImp"}] 3245rwer 20191228  NoImp