Has there been any change in the format of using function

I have the query in below format and it runs in ES 2.4

{"query":{"function_score":{"filter":{"bool":{"must":[{"exists":{"field":"x"}},{"query_string":{"query":"en","fields":["locale"]}},{"query_string":{"query":"US","fields":["channel"]}},{"query_string":{"query":"UG","fields":["usergroups"]}}]}},"query":{"bool":{"should":{"multi_match":{"query":"refund","fields":["doc","key","title","title.standard_analyzed^3","x"],"type":"phrase","slop":20}},"must":{"multi_match":{"fuzziness":"0","query":"refund","prefix_length":"6","fields":["doc","key","title","title.standard_analyzed^3","x"],"max_expansions":"30"}}}},"functions":[{"field_value_factor":{"field":"usage","factor":1,"modifier":"log2p","missing":1}}]}},"from":0,"size":21}

But when I try the same query in 6.8 it returns errors {"error":{"root_cause":[{"type":"parsing_exception","reason":"no [query] registered for [function_score]",

If I put filters inside query, I get the response but the order of the docs don't match due to the difference in score

CodePudding user response：

There should only be the "query" key below the function score. You have to add the filter in the bool query. I don't know about your mapping but I would use the "Term" query instead of the query string.

{
  "query": {
    "function_score": {
      "query": {
        "bool": {
          "filter": { 
            "bool": {
              "must": [
                {
                  "exists": {
                    "field": "x"
                  }
                },
                {
                  "query_string": {
                    "query": "en",
                    "fields": [
                      "locale"
                    ]
                  }
                },
                {
                  "query_string": {
                    "query": "US",
                    "fields": [
                      "channel"
                    ]
                  }
                },
                {
                  "query_string": {
                    "query": "UG",
                    "fields": [
                      "usergroups"
                    ]
                  }
                }
              ]
            }
          },
          "should": {
            "multi_match": {
              "query": "refund",
              "fields": [
                "doc",
                "key",
                "title",
                "title.standard_analyzed^3",
                "x"
              ],
              "type": "phrase",
              "slop": 20
            }
          },
          "must": {
            "multi_match": {
              "fuzziness": "0",
              "query": "refund",
              "prefix_length": "6",
              "fields": [
                "doc",
                "key",
                "title",
                "title.standard_analyzed^3",
                "x"
              ],
              "max_expansions": "30"
            }
          }
        }
      },
      "functions": [
        {
          "field_value_factor": {
            "field": "usage",
            "factor": 1,
            "modifier": "log2p",
            "missing": 1
          }
        }
      ]
    }
  },
  "from": 0,
  "size": 21
}

About FunctionScore (doc 6.8)