Comparing dimensions in druid - druid

Question

I recently started experimenting with druid. I have a use case which I'm not able to solve. I have 3 date columns primary_date, date_1 and date_2, amount and client.
I wanted to calulate sum(amount) when date_1 > date_2 when granularity is month. I wanted to calculate this for each month in 6 month interval for each client.
I also wanted to calcutate sum(amount) when date_1 > max(bucket date) for each bucket for 6 months for each client.
{
"queryType" : "groupBy",
"dataSource" : "data_source_xxx",
"granularity" : "month",
"dimensions" : ["client"],
"intervals": ["2019-01-01/2019-07-01"],
"aggregations":[{"type": "doubleSum", "name": "total_amount", "fieldName": "amount"}],
"filter" : {
"type": "select",
"dimension": "client",
"value": "client"
}
}
I wanted to modify the above query to have additional filters I have mentioned.
Any help is highly appreciated.
Thanks

Answer 1

I think you can realize this by using a virtual column, which does the date comparison. Then you should be able to use the virtual column in a filtered aggregation, which only applies the aggregation if the filter matches.
This is not tested, but I think something like this should work:
{
"queryType": "groupBy",
"dataSource": "data_source_xxx",
"intervals": [
"2019-01-01T00:00:00.000Z/2019-07-01T00:00:00.000Z"
],
"dimensions": [
{
"type": "default",
"dimension": "client",
"outputType": "string",
"outputName": "client"
}
],
"granularity": "month",
"aggregations": [
{
"type": "filtered",
"filter": {
"type": "selector",
"dimension": "isOlder",
"value": "1"
},
"aggregator": {
"type": "doubleSum",
"name": "sumAmount",
"fieldName": "amount"
}
}
],
"virtualColumns": [
{
"type": "expression",
"name": "isOlder",
"expression": "if( date_1 > date_2, '1', '0')",
"outputType": "string"
}
],
"context": {
"groupByStrategy": "v2"
}
}
I have created this using this PHP code using this package: https://github.com/level23/druid-client
$client = new DruidClient(['router_url' => 'http://127.0.0.1:8888']);
// Build a select query
$builder = $client->query('data_source_xxx', Granularity::MONTH)
->interval("2019-01-01/2019-07-01")
->select(['client'])
->virtualColumn("if( date_1 > date_2, '1', '0')", 'isOlder')
->sum('amount', 'sumAmount', DataType::DOUBLE, function(FilterBuilder $filterBuilder){
$filterBuilder->where('isOlder', '=', '1');
});
echo $builder->toJson();