elasticsearch: Add weight for each match of array - elasticsearch

Question

I want to add a weight for each match (instead of adding a weight once if one of those matched):
Having docs like this:
[{
"username": "xyz",
"categories": [
{
"category.id": 1
},
{
"category.id": 2
}
]
}, {
"username": "xyz2",
"categories": [
{
"category.id": 1
}
]
}]
And currently, I have this query:
{
"query": {
"filtered": {
"query": {
"function_score": {
"query": {
"bool": {}
},
"score_mode": "sum",
"boost_mode": "sum",
"functions": [
{
"weight": 1.1,
"filter": {
"terms": {
"category.id": [
1,
2
]
}
}
}
]
}
},
"filter": {
"bool": {
"must_not": [
{
"terms": {
"_id": [
8
]
}
}
]
}
}
}
},
"from": 0,
"size": 30
}
With this query, both entries would receive a single weight of 1.1, but I want the first entry to get 2 * 1.1 because 2 categories are matched. How could I achieve that?
EDIT: Sorry, I missed to add elastic search version. It's 1.7.2.

Answer 1

This might be a bit cumbersome, since for multiple IDs that query will need to have multiple statements, but I don't think there is any other way. Also, notice that your field referencing is not complete - it should be categories.category.id to be correct. Also, be careful when upgrading with dots in field names. This changed in some releases over time.
{
"query": {
"filtered": {
"query": {
"function_score": {
"query": {
"match_all": {}
},
"score_mode": "sum",
"boost_mode": "sum",
"functions": [
{
"weight": 1.1,
"filter": {
"term": {
"categories.category.id": 1
}
}
},
{
"weight": 1.1,
"filter": {
"term": {
"categories.category.id": 2
}
}
}
]
}
},
"filter": {
"bool": {
"must_not": [
{
"terms": {
"_id": [
8
]
}
}
]
}
}
}
},
"from": 0,
"size": 30
}