aggregations merged in hits in elasticsearch - sql

Question

Just for an example, let's say I have a database, or an elastic index, holding sales persons and also all their customer visits past and into the future.
Lets also say I want to produce a list of these sales persons and show how many customer visits they have scheduled.
In SQL I would do something like this:
(mind: SQL is probably not all that correct, because it is just written here and just for telling what I am intending to do)
select foo, bar, sum(baz) from table_barbaz
where appointment_date > now()
group by bar
is it possible to get the same result in Elastic search? Like a list of documents sort of looking like this:
{
"foo": "Salesmen John",
"bar": "Client visit this week",
"sum_baz": 99
}
Not sure if this is related to nested aggregations or something else.
Below is a mapping that could have been used in this example. As the real mapping is internal IP, I don't really want to share it publicly.
{
"mappings": {
"properties": {
"salesman_id": {
"type": "integer"
},
"salesman_name": {
"type": "keyword"
},
"customer_visit": {
"type": "integer"
},
"customer_visit_start_date": {
"type": "date",
"format": "yyyy-MM-dd||strict_date"
},
"customer_visit_end_date": {
"type": "date",
"format": "yyyy-MM-dd||strict_date"
}
}
}
}

Answer 1

Then, an aggregation query like the following one would give you the number of customer visits for each salesman, for each day:
{
"size": 0,
"aggs": {
"salesmen": {
"terms": {
"field": "salesman_name",
"size": 20
},
"aggs": {
"days": {
"date_histogram": {
"field": "customer_visit_start_date",
"interval": "day"
},
"aggs": {
"visits": {
"sum": {
"field": "customer_visit"
}
}
}
}
}
}
}
}