Elasticsearch过滤器

Question

I will receive the filter inputs from the front-end via node js some may be null or empty but in the elasticsearch query filter all the field should be present . How to get response even the inputs are empty for some filters ?

 elasticClient.search({
                 index: 'pubmed-index',
                 type: 'pubmed-paper',
                 body: {
                  query: {
                      bool: {
                          must: {
                              match: {
                                  Abstract: `${searchKeyword}`
                              }
                          },
                          filter:
                          {"or":[{
                                  term: 
                                  {
                                  "Publication Type": `${searchPublicationType}`
                                  }},
                              {

                              "range": {
                                "Date Completed": {
                                    "gte" :`${searchGreaterYear}||/y`,
                                    "lte" : `${searchLesserYear}||/y`,
                                    "format" :"yyyy"
                                }
                            }
                          }
                           ]}



                      }
                  }
              }
               }).then(function (resp) {
                   console.log(resp.hits.hits);
                   return res.json(resp.hits.hits)
               }, function (err) {
                   console.log(err.message);
                   return res.json(err.message)
               });

I need the output either for publication type or date completed if any of the fields are missing

Answer 1

I can suggest you take a look on the search template functionality provided by Elasticsearch.

It uses mustache as a template language and allows to have for example conditional clauses:

{
  "query": {
    "bool": {
      "must": {
        "match": {
          "line": "{{text}}" 
        }
      },
      "filter": {
        {{#line_no}} 
          "range": {
            "line_no": {
              {{#start}} 
                "gte": "{{start}}" 
                {{#end}},{{/end}} 
              {{/start}} 
              {{#end}} 
                "lte": "{{end}}" 
              {{/end}} 
            }
          }
        {{/line_no}} 
      }
    }
  }
}

and few more options.

I was using it on production for a similar case - to omit some filters when a user does not put any value for them.