ElasticSearch Nested Filter and Aggregation - elasticsearch

Question

So I have this mapping:
"employee": {
"properties": {
"DaysOff": {
"type": "nested",
"properties": {
"Date": {
"type": "date",
"format": "strict_date_optional_time||epoch_millis"
},
"Days": {
"type": "double"
},
"ID": {
"type": "long"
}
}
}
}
}
So basically a employee can have days off. Each day off they have is stored in an array under the property DaysOff. Days can be a fraction of a day, so if an employee took half a day off then it would be 0.5.
So I have this search:
{
"size": 45,
"filter": {
"nested": {
"path": "DaysOff",
"filter": {
"range": {
"DaysOff.Date": {
"from": "now-2M",
"to": "now"
}
}
}
}
}
}
which brings me back 45 documents. which is correct. I'm just can't figure out how to now apply an aggregation to these documents in order to get back the sum of all the days that have been taken.
Using this resource I tried this aggs but didn't get me the correct result:
{
"size": 45,
"filter": {
"nested": {
"path": "DaysOff",
"filter": {
"range": {
"DaysOff.Date": {
"from": "now-2M",
"to": "now"
}
}
}
}
},
"aggs": {
"sum_docs": {
"nested": {
"path": "DaysOff"
},
"aggs": {
"stepped_down": {
"sum": {
"field": "DaysOff.Days"
}
}
}
}
}
}

Answer 1

You need to filter on those nested documents to get the correct results, From the docs
Because nested documents are indexed as separate documents, they can only be accessed within the scope of the nested query,
I created index like this
POST employee
{
"mappings": {
"emp_map": {
"properties": {
"DaysOff": {
"type": "nested",
"properties": {
"Date": {
"type": "date",
"format": "strict_date_optional_time||epoch_millis"
},
"Days": {
"type": "double"
},
"ID": {
"type": "long"
}
}
},
"name": {
"type": "string"
}
}
}
}
},
Then I indexed few documents like this,
PUT employee/emp_map/1
{
"name" : "messi",
"DaysOff" : [
{
"Date" : "2015-11-01",
"Days" : 1,
"ID" : 11
},
{
"Date" : "2014-11-01",
"Days" : 2,
"ID" : 11
},
{
"Date" : "2015-12-01",
"Days" : 0.5,
"ID" : 11
}
]
}
PUT employee/emp_map/2
{
"name" : "ronaldo",
"DaysOff" : [
{
"Date" : "2015-10-01",
"Days" : 3,
"ID" : 12
},
{
"Date" : "2014-11-01",
"Days" : 2,
"ID" : 12
},
{
"Date" : "2015-12-01",
"Days" : 0.5,
"ID" : 12
}
]
}
PUT employee/emp_map/3
{
"name" : "suarez",
"DaysOff" : [
{
"Date" : "2015-11-01",
"Days" : 4,
"ID" : 13
},
{
"Date" : "2015-11-09",
"Days" : 2,
"ID" : 13
},
{
"Date" : "2015-12-01",
"Days" : 1.5,
"ID" : 13
}
]
}
This is my query, notice the filter aggregation in nested aggregation, without that ES will give you sum of all the days taken off.
GET employee/_search
{
"query": {
"bool": {
"filter": {
"nested": {
"path": "DaysOff",
"query": {
"range": {
"DaysOff.Date": {
"from": "now-2M",
"to": "now"
}
}
}
}
}
}
},
"aggs": {
"emp_name": {
"terms": {
"field": "name",
"size": 10
},
"aggs": {
"nesting": {
"nested": {
"path": "DaysOff"
},
"aggs": {
"filter_date": {
"filter": {
"range": {
"DaysOff.Date": {
"from": "now-2M",
"to": "now"
}
}
},
"aggs": {
"sum_taken_off_days": {
"sum": {
"field": "DaysOff.Days"
}
}
}
}
}
}
}
}
},
"size": 0
}
This is the result I get,
"aggregations": {
"emp_name": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "messi",
"doc_count": 1,
"nesting": {
"doc_count": 3,
"filter_date": {
"doc_count": 2,
"sum_taken_off_days": {
"value": 1.5
}
}
}
},
{
"key": "ronaldo",
"doc_count": 1,
"nesting": {
"doc_count": 3,
"filter_date": {
"doc_count": 1,
"sum_taken_off_days": {
"value": 0.5
}
}
}
},
{
"key": "suarez",
"doc_count": 1,
"nesting": {
"doc_count": 3,
"filter_date": {
"doc_count": 3,
"sum_taken_off_days": {
"value": 7.5
}
}
}
}
]
}
}
P.S : This is per employee, you can remove emp_name terms aggregation to get sum of all employees.