reading nested json data from Flex table in vertica - json

Question

I have this json file.
[
{
"Modified": "2016-09-0",
"Id": 16,
"Name": "ABC",
"Filters": [],
"ScoreComponents":[
{
"Id": 86,
"Name": "Politeness",
"Bins": [],
"Ranges": [
{
"ComponentId": 86,
"LastUser": "CDE\\John.Doe"
},
{
"ComponentId": 86,
"LastUser": "CDE\\John.Doe"
}
],
"Filters": []
},
{
"Id": 87,
"Name": "Empathy",
"Bins": [],
"Ranges": [
{
"ComponentId": 87,
"LastUser": "CDE\\John.Doe"
}
],
"Filters": [
{
"ComponentID": -30356,
"BucketID": 81
}
]
},
{
"Id": 88,
"Name": "Ownership",
"Bins": [],
"Ranges": [
{
"ComponentId": 88,
"User": "CDE\\John.Doe"
}
],
"Filters": []
}]
}
]
I have loaded this file In Vertica flex table
CREATE FLEX TABLE flex_test();
copy events_stg.flex_test from LOCAL 'C:/test2.json' PARSER fjsonparser (flatten_maps= true, flatten_arrays = false)
I want to read all data from ScoreComponents including nested arrays.
I tried query this query
select "Id" as scoreid,mapitems("ScoreComponents") OVER(PARTITION BY
"Id") from flex_test
getting output like:
I just dont understand those small squares in output. I am a student and this vertica DB and Flex tables are new me.
I have tried with flatten_arrays = true but its giving me empty result set.

Answer 1

You're getting squares because the values field contains a binary VMap.
This should do it:
create flex table so_flex();
create table so_score_components(
id int,
name varchar(100)
);
create table so_ranges(
parent_id int,
component_id int,
last_user varchar(100)
);
create table so_filters(
parent_id int,
component_id int,
bucket_id int
);
copy so_flex from local 'E:\Demos\so.json'
parser fjsonparser(start_point='ScoreComponents',
flatten_maps = false, flatten_arrays = false);
insert into so_score_components(id, name)
select id::int, name::varchar from so_flex;
insert into so_ranges(parent_id, component_id, last_user)
select id::int, values['ComponentId']::int, values['LastUser']::varchar
from (
select id, mapitems(ranges) over (partition by id)
from so_flex
) t;
insert into so_filters(parent_id, component_id, bucket_id)
select id::int, values['ComponentID']::int, values['BucketID']::int
from (
select id, mapitems(filters) over (partition by id)
from so_flex
) t;