# Merging documents based on matched fields values

**URL:** <https://discuss.elastic.co/t/merging-documents-based-on-matched-fields-values/249728>\
**Category:** Elasticsearch\
**Created:** [September 24, 2020, 2:47am UTC](https://discuss.elastic.co/t/merging-documents-based-on-matched-fields-values/249728 "2020-09-24T02:47:47Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![Hendrik\_Muhs](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/hendrik_muhs/32/25802_2.png) [@Hendrik\_Muhs](https://discuss.elastic.co/u/Hendrik_Muhs)\
**Post date:** [September 24, 2020, 6:24am UTC](https://discuss.elastic.co/t/merging-documents-based-on-matched-fields-values/249728/2 "2020-09-24T06:24:17Z")

</div>

This can be achieved by grouping docs using `job_name` and `build_number` and than aggregate the docs with a `scripted_metric`. A perfect fit for that is a [composite aggregation](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-composite-aggregation.html). `job_name` and `build_number` are the sources, the `scripted_metric` that merges the fields your aggregation.

However, you want to visualize on top of that, so I think you want to have the merged documents in an index. That's where [transform](https://www.elastic.co/guide/en/elasticsearch/reference/current/transforms.html) comes into play. It basically runs a composite aggregation, takes the results and writes the output into a new index. You can set it up to run continuously, so it will consume your new incoming data (you need a timestamp for that, but I guess you have that). In transform `job_name` and `build_number` would be your `group_by`.

Regarding the `scripted_metric` aggregation, please have a look [here](https://www.elastic.co/guide/en/elasticsearch/reference/current/transforms.html). The examples are not transform specific, but work in aggregations.

Here is a more specific example, I found:

```auto
"scripted_metric": {
          "init_script": "state.join = new HashMap()",
          "map_script": "String[] fields = new String[] {'name', 'best_friend', 'hobby'}; for (e in fields) { if (doc.containsKey(e)) {state.join.put(e, doc[e])}}",
          "combine_script": "return state.join",
          "reduce_script": "String[] fields = new String[] {'name', 'best_friend', 'hobby'}; Map j=new HashMap(); for (s in states) {for (e in fields) { if (s.containsKey(e)) {j.put(e, s[e].get(0))}}} return j;"
        }

```

---

_[View the full topic](https://discuss.elastic.co/t/merging-documents-based-on-matched-fields-values/249728)._