Query for nested fields returns results as if there was no nested mapping - elasticsearch

Question

I am having difficulties understanding, why a query across nested fields is returning unexpected results.
I have the following template for my index
PUT /_template/nested_test
{
"index_patterns": [ "nested-*" ],
"settings": { "index.mapping.coerce": false },
"mappings": {
"dynamic": "strict",
"properties" {
"vNested": {
"type": "nested",
"properties": {
"v1": { "type": "keyword" },
"v2": {
"properties": {
"v21": {
"type": long"
}
}
}
}
}
}
}
}
I will post two documents to an index that matches the template.
POST /nested-example/_doc
{
"vNested": [
{
"v1": "User1",
"v2": {
"v21": 1
}
},
{
"v1": "User3",
"v2": {
"v21": 3
}
}
]
}
POST /nested-example/_doc
{
"vNested": [
{
"v1": "User1",
"v2": {
"v21": 3
}
},
{
"v1": "User2",
"v2": {
"v21": 2
}
}
]
}
Now I will create a query with the goal of only getting the results of those documents, where there exists User1 with a corresponding v21 value of 3. As far as I understand, my nested mapping should ensure that I will only get the second document as query result.
The following query:
GET /nested-example/_search
{
"query" : {
"bool": {
"filter": {
"bool": {
"must": [
{
"nested: {
"path": "vNested",
"query": {
"match": {
"vNested.v1": "User1"
}
}
}
},
{
"nested: {
"path": "vNested",
"query": {
"match": {
"vNested.v2.v21": "3"
}
}
}
}
]
}
}
}
}
}
returns both documents, not only the single document that I expected
I understand that the query string is not the most elegant - this is due to some business logic + front-end framework logic in place for creating the query strings based on user input and any suggestions on how to remove redundancies there are welcome as well.
However I struggle to understand why does this query return both documents including the one where the vNested object with v1=User1, and v21=1. Shouldn't the nested mapping of the vNested field prevent just that issue?

Answer 1

You need to use bool/must query inside the nested query since you are querying on a single object and not on multiple objects. Modify your query as
{
"query": {
"bool": {
"filter": {
"bool": {
"must": [
{
"nested": {
"path": "vNested",
"query": {
"bool": {
"must": [
{
"match": {
"vNested.v1": "User1"
}
},
{
"match": {
"vNested.v2.v21": "3"
}
}
]
}
},
"inner_hits":{}
}
}
]
}
}
}
}
}
Search Result is
"hits": [
{
"_index": "nested-example",
"_type": "_doc",
"_id": "AAu0IXkBKyWl6Va6kmTU",
"_score": 0.0,
"_source": {
"vNested": [
{
"v1": "User1",
"v2": {
"v21": 3
}
},
{
"v1": "User2",
"v2": {
"v21": 2
}
}
]
},
"inner_hits": {
"vNested": {
"hits": {
"total": {
"value": 1,
"relation": "eq"
},
"max_score": 1.6931472,
"hits": [
{
"_index": "nested-example",
"_type": "_doc",
"_id": "AAu0IXkBKyWl6Va6kmTU",
"_nested": {
"field": "vNested",
"offset": 0
},
"_score": 1.6931472,
"_source": {
"v1": "User1",
"v2": {
"v21": 3
}
}
}
]
}
}
}
}
]