The get_json_object supports a restricted version of JSON object and path
expressions. It supports arrays at non-root level. You can see the details by
hive> describe function extended get_json_object;
On Aug 18, 2010, at 3:07 PM, Steven Wong wrote:
I have a string column that contains a JSON array on each row. Calling the
function get_json_object on that column always returns NULL:
$ hive -e "select cdnbwdata, get_json_object(cdnbwdata, '$'),
get_json_object(cdnbwdata, '$[0].rtt'), get_json_object(cdnbwdata, '$.rtt')
from mytable"
[{"id":9,"ip":"173.223.232.50","rtt":71,"bw":41943}] NULL NULL NULL
If I replace the array with its 0th element, then get_json_object works:
$ hive -e "select cdnbwdata, get_json_object(cdnbwdata, '$'),
get_json_object(cdnbwdata, '$[0].rtt'), get_json_object(cdnbwdata, '$.rtt')
from mytable"
{"id":9,"ip":"173.223.232.32","rtt":71,"bw":4211}
{"id":9,"bw":4211,"rtt":71,"ip":"173.223.232.32"} NULL 71
Is it a get_json_object bug in handling arrays, or am I doing something wrong?
Hive version is 0.5.
Thanks.
Steven
