Dynamic Parameter Query

# define a query template with 2 optional parameters, 0 - 2 could be passed for filtering
# {{#state_p}} {{/state_p}} indicates optional parameter's present
# match_all is here to make json valid, it is like 1=1 in sql to make where clause valid in AND condition.
# depends on situation, match_none could be used, sql equivalent of 1=1, in OR condition 

PUT _scripts/dynamic-parm-template
{
  "script": {
    "lang": "mustache",
    "source": """{
      "query": {
        "bool": {
          "filter": [
            {{#state_p}} {"term": {"state": "{{state_p}}"}}, {{/state_p}}
            {{#zip_p}} {"term": {"zip": "{{zip_p}}"}}, {{/zip_p}}
            { "match_all": {}}
            ]
        }
      }
    },
    "params": {
      "state_p": "tx",
      "zip_p": "75205"
    }
    """
  }
}
# response
{
  "acknowledged": true
}

# validate template

POST _render/template
{
  "id": "dynamic-parm-template",
  "params": {
    "state_p": "tx",
    "zip_p": "75204"
  }
}
# response, shows what query looks like after parameter applied
{
  "template_output": {
    "query": {
      "bool": {
        "filter": [
          {
            "term": {
              "state": "tx"
            }
          },
          {
            "term": {
              "zip": "75204"
            }
          },
          {
            "match_all": {}
          }
        ]
      }
    }
  }
}

# actual query against ix_state_zip index
GET ix_state_zip/_search/template
{
  "id": "dynamic-parm-template",
  "params": {
    "state_p": "tx",
    "zip_p": "75205"
  }
}