HIVE: how to access elements in a MAP object - dictionary

Question

in my HIVE table MYTABLE I have one column "MYCOL" that contains this:
{"id": "a651b57f",
"items": {
"ITEM1": {
"code": "CODE1",
"name": "NAME1"},
"ITEM2": {
"code": "CODE2",
"name": "NAME2"}},
"myinfo": {
"c7daf1a9": {
"id": "c7daf1a9",
"name": "newname",
"type": "newtype",
"appliedto": ["ITEM1", "ITEM2"]}},
"info2": 12}
I would like to access the elements into "myinfo" and I tried something like this:
select GET_JSON_OBJECT(t.MYCOL,'$.myinfo') FROM MYTABLE
but it doesn't work....
may someone help me?
thanks

Answer 1

Make sure the data in HDFS file have one line for each json row (not multiple new lines for one row).
If json row is having multiple new lines then we need to replace all newlines for each row before storing into HDFS.
Example:
HDFS file data:
{"id": "a651b57f","items": {"ITEM1": {"code": "CODE1","name": "NAME1"},"ITEM2": {"code": "CODE2","name": "NAME2"}},"myinfo": {"c7daf1a9": {"id": "c7daf1a9","name": "newname","type": "newtype","appliedto": ["ITEM1", "ITEM2"]}},"info2": 12}
Hive:
with cte as (select string('{"id": "a651b57f","items": {"ITEM1": {"code": "CODE1","name": "NAME1"},"ITEM2": {"code": "CODE2","name": "NAME2"}},"myinfo": {"c7daf1a9": {"id": "c7daf1a9","name": "newname","type": "newtype","appliedto": ["ITEM1", "ITEM2"]}},"info2": 12}')my_col) --sample data
select get_json_object(my_col,'$.myinfo')jsn from cte;
Output:
{"c7daf1a9":{"id":"c7daf1a9","name":"newname","type":"newtype","appliedto":["ITEM1","ITEM2"]}}
Update
--to access name subfield we need to specify the path of json object
hive> select get_json_object(my_col,'$.myinfo.c7daf1a9.name')jsn from <table_name>;
--result
newname
hive> select get_json_object(my_col,'$.myinfo.c7daf1a9.appliedto')jsn from <table_name>;
--result
["ITEM1","ITEM2"]
hive> select get_json_object(my_col,'$.myinfo.c7daf1a9.appliedto[0]')jsn from <table_name>;
--result
ITEM1