Update only specific field value in elasticsearch

Question

Is it possible to update some specific fields value in elasticsearch with out overwriting other fields. ?

Answer 1

If you would like to update the existing field value only then you must try this solution:

POST IndexName/_update_by_query
{
  "script": {
    "source": """

   if (ctx._source?.Field != null) 
    {  
        ctx._source.remove('Field');
        ctx._source.put('Field', 'Value');
    }   
    """,
    "lang": "painless"
  },
  "query": {
    "terms": {
        "_id": [
          1 (Replace with Document ID)
        ]
      }
  }
}

If you would like to add new field with value then you must try this solution:

POST IndexName/_update_by_query
{
  "script": {
    "source": """

   if (ctx._source?.NewField == null) 
    {  
        ctx._source.hf.put('NewField', 'Value');
    }   
    """,
    "lang": "painless"
  },
  "query": {
    "terms": {
        "_id": [
          1 (Replace with Document ID)
        ]
      }
  }
}