Use Filtered Aggregator return null but expect 0

[sh-learn]

I recently encountered a problem with druid. When using the filter aggregator to count the total number of times a condition is met, since there is no data that satisfies the filter condition, it returns null when LongSum is performed, but expects to return 0. I don't know if there is a solution? The version of druid used is 0.10.1.

filtered aggregator:
{
"type": "filtered",
"filter": {
"type": "selector",
"dimension": "xxx",
"value": "yyy"
},
"aggregator": {
"type": "longSum",
"name": "value",
"fieldName": "zzz"
}
}
result:
{
"version" : "v1",
"timestamp" : "2018-08-01T00:00:00.000+08:00",
"event" : {
"value" : null
}

[stale]

This issue has been marked as stale due to 280 days of inactivity. It will be closed in 2 weeks if no further activity occurs. If this issue is still relevant, please simply write any comment. Even if closed, you can still revive the issue at any time or discuss it on the dev@druid.apache.org list. Thank you for your contributions.

[github-actions]

This issue has been marked as stale due to 280 days of inactivity.
It will be closed in 4 weeks if no further activity occurs. If this issue is still
relevant, please simply write any comment. Even if closed, you can still revive the
issue at any time or discuss it on the dev@druid.apache.org list.
Thank you for your contributions.