Multi level nested objects inner_hits not working (only root level working)

[distributedlock]

.

[martijnvg]

@ranadeeppolavarapu the inner_hits syntax in the query dsl doesn't support proper nested. For now you should use the top level inner_hits syntax: https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-inner-hits.html#top-level-inner-hits

This issue is related to this ticket: #11118
Although this ticket is about parent/child inner hits, the the nested inner_hits in the query dsl doesn't work there too and this should be fixed

[clintongormley]

Closing as duplicate of #11118

[martijnvg]

@ranadeeppolavarapu the following query should work:

curl -XGET "http://localhost:9200/_search" -d'
{
  "query": {
    "nested": {
      "path": "cars",
      "query": {
        "nested": {
          "path": "cars.manufacturers",
          "query": {
            "match": {
              "cars.manufacturers.country": "Japan"
            }
          }
        }
      }
    }
  },
  "inner_hits": {
    "cars": {
      "path": {
        "cars": {
          "query": {
            "nested": {
              "path": "cars.manufacturers",
              "query": {
                "match": {
                  "cars.manufacturers.country": "Japan"
                }
              }
            }
          },
          "inner_hits": {
            "manufacturers": {
              "path": {
                "cars.manufacturers": {
                  "query": {
                    "match": {
                      "cars.manufacturers.country": "Japan"
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}'

Downside that It is more verbose, because the query needs to be repeated on each nested level. When the embedded query dsl inner_hits syntax also properly supports multiple level of nested object fields and parent child relations then your query should work too.

[abulhol]

+1
I am wondering why the reference includes this paragraph:
https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-inner-hits.html#hierarchical-nested-inner-hits
which seems exactly the part that is not working

[black-square]

This bug is closed as well as #11118, but the original example from @ranadeeppolavarapu still doesn't work on 2.4. Should it be reopen again?

[martijnvg]

@black-square The bug was only fixed in 5.0.x. Fixing it required a refactoring that didn't make its way back in 2.4

[abhishek5678]

Hi Guys,
In this data when i am trying with one level nested data then it's working fine but when i am adding one more nested data then it's not working if anybody will be knows about that then please reply me.I am sending my document data and mapping file also.

POST /test_word14/doc/1
{
"name": "Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)",
"depth": 1,
"children": [{
"name": "Nutritional anemias (D50-D53)",
"depth": 2,
"children": [{
"code": "D50",
"name": "Iron deficiency anemia",
"depth": 3,
"children": [{
"code": "D50.0",
"name": "Iron deficiency anemia secondary to blood loss (chronic)",
"depth": 4
}, {
"code": "D50.1",
"name": "Sideropenic dysphagia",
"depth": 4
}, {
"code": "D50.8",
"name": "Other iron deficiency anemias",
"depth": 4
}, {
"code": "D50.9",
"name": "Iron deficiency anemia, unspecified",
"depth": 4
}]
}]
}]
}

(mapping file)
PUT /test_word16
{
"mappings": {
"doc": {
"properties": {
"name": { "type": "string" },
"depth": {"type":"long"},
"children": {
"type": "nested",
"properties": {
"name": { "type": "string" },
"depth": { "type": "long" },
"children": {
"type": "nested",
"properties": {
"code": { "type": "string" },
"name": { "type": "string" },
"depth": { "type": "long" },
"children": {
"type": "nested",
"properties": {
"code": { "type": "string" },
"name": { "type": "string" },
"depth": { "type": "long" },
}
}
}
}
}
}
}
}
}
}

please tell me what is the query i am applying here.i am applying the query like this:
GET /icd10_codes/doc/_search
{
"_source": false,
"query": {
"nested": {
"path": "children",
"query": {
"nested": {
"path": "children.children",
"query": {
"nested": {
"path": "children.children.children",
"query": {
"bool": {
"must": [
{
"match": {
"children.children.name": "Iron"
}
}
]
}
},
"inner_hits": {
"_source": {
"excludes":["name"]
}
}
}
}
}
}
}
}

[abhishek5678]

Hi @ranadeeppolavarapu

when i am running your example then it is not working it's showing like that:Unknown key for a START_OBJECT in [inner_hits]

[ssllmit]

Multi-level nested queries with inner_hits still appears to be an issue with Elasticsearch 7.10.0:

Create the test index

curl -XPUT "http://localhost:9200/test_index_github" -H 'Content-Type: application/json' -d'
{
  "settings" : {
    "index" : {
      "number_of_shards" : 10,
      "number_of_replicas" : 1
    }
  }
}
'

curl -XPUT "http://localhost:9200/test_index_github/_mapping" -H 'Content-Type: application/json' -d'
{
  "properties": {
    "cars": {
      "type": "nested",
      "properties": {
        "manufacturers": {
          "type": "nested",
          "properties": {
            "country": {
              "type": "text"
            },
            "name": {
              "type": "text"
            }
          }
        },
        "model": {
          "type": "text"
        },
        "make": {
          "type": "text"
        }
      }
    },
    "last_name": {
      "type": "text"
    },
    "first_name": {
      "type": "text"
    }
  }
}
'

curl -XPUT "http://localhost:9200/test_index_github/_doc/0" -H 'Content-Type: application/json' -d'
{
  "first_name": "Zach",
  "last_name": "Foobar",
  "cars": [
    {
      "make": "Saturn",
      "model": "SL",
      "manufacturers": [
        {
          "name": "Saturn",
          "country": "USA"
        },
        {
          "name": "Honda",
          "country": "Canada"
        }
      ]
    },
    {
      "make": "Subaru",
      "model": "Imprezza",
      "manufacturers": [
        {
          "name": "Subaru",
          "country": "Japan"
        },
        {
          "name": "Daimler",
          "country": "Germany"
        }
      ]
    }
  ]
}
'

Query the test index:

curl -XPOST "http://localhost:9200/test_index_github/_search?pretty" -H 'Content-Type: application/json' -d'
{        
  "query": {
    "nested": {
      "path": "cars",
      "query": {
        "nested": {
          "path": "cars.manufacturers",
          "query": {
            "match": {                             
              "cars.manufacturers.country": "Japan"
            }
          },              
          "inner_hits": {}
        }
      },              
      "inner_hits": {}
    }
  }
}
'

Result:

{
  "took" : 19,
  "timed_out" : false,
  "_shards" : {
    "total" : 10,
    "successful" : 8,
    "skipped" : 0,
    "failed" : 2,
    "failures" : [
      {
        "shard" : 7,
        "index" : "test_index_github",
        "node" : "FohAXm0YRWSJR72OyyNqHA",
        "reason" : {
          "type" : "index_out_of_bounds_exception",
          "reason" : "index_out_of_bounds_exception: Index: 1, Size: 1"
        }
      }
    ]
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 1.2039728,
    "hits" : [ ]
  }
}

[ssllmit]

Oh I see—the syntax has changed to accommodate this capability: https://www.elastic.co/guide/en/elasticsearch/reference/7.10/inner-hits.html

Key sentence: "This indirect referencing is only supported for nested inner hits."

This query works:

curl -XPOST "http://localhost:9200/test_index_github/_search?pretty" -H 'Content-Type: application/json' -d'
{
  "query": {
    "nested": {
      "path": "cars.manufacturers",
      "query": {
        "match": {
          "cars.manufacturers.country": "Japan"
        }
      },
      "inner_hits": {}
    }
  }
}
'