How to Boost a field based on condition in ElasticSearch

Question

I am having a query structure like

{
  "sort": {},
  "query": {
    "bool": {
      "should": [
        {
          "match_phrase": {
            "user_categories": "Grant Writing"
          }
        },
        {
          "match_phrase": {
            "user_agencies": "Census"
          }
        },
        {
          "match_phrase": {
            "user_agencies": "MDA"
          }
        },
        {
          "match_phrase": {
            "user_agencies": "OSD"
          }
        }
      ]
    }
  },
  "size": 500,
  "from": 0
}

Suppose this will return a list of 10 users.

What I need to get is, the user having Agency: 'Census' to be the first one in the search result (boost the results having Census as agency). How can we do this?

Answer 1

The following will do it. I converted some of the match_phrase queries to match queries as they contain only single terms

{
  "sort": {},
  "query": {
    "bool": {
      "should": [
        {
          "match_phrase": {
            "user_categories": "Grant Writing"
          }
        },
        {  
          "match": {
            "user_agencies": { 
              "query": "Census",
              "boost": 3
            }
          }
        },
        {
          "match": {
            "user_agencies": {
              "query": "MDA",
          }
        },
        {
          "match": {
            "user_agencies": {
              "query": "OSD",
          }
        }
      ]
    }
  },
  "size": 500,
  "from": 0
}