Return JSON array in query

[Jonatas Freitas]

Table structure
session_id String
details String (with JSON)

RAW data example
1;{"a": 2}
1;{"b": 2}
2;{"d": 2}
2;{"b": 2}

Expected result
1;[{"a": 2}, {"b": 2}]
2;[{"d": 2}, {"b": 2}]

Have any way?

[Denis Zhuravlev]

select a, concat('[',arrayStringConcat(groupArray(x), ','),']')
from (
select 1 as a, '{"a": 2}' as x
union all
select 1 as a, '{"b": 2}' as x
) group by a

Check https://clickhouse.yandex/docs/en/formats/jsoneachrow/ maybe you will able to use clickhouse-client to render json from your data.