# How to query multiple indexes in ElasticSearch 5.6 when they have different parent-child mappings?
**URL:** https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300
**Category:** Elasticsearch
**Created:** [October 25, 2017, 9:11pm UTC](https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300 "2017-10-25T21:11:17Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@sclaggett](https://discuss.elastic.co/u/sclaggett)
#### Post date: [October 25, 2017, 9:11pm UTC](https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300/1 "2017-10-25T21:11:17Z")
We're attempting to retrieve results from several different Elasticsearch indexes and sort them by a common field. The way we're approaching this is to create a boolean query that is composed of multiple _should_ statements with the first _should_ statement selecting items from index A, the second from index B, etc.
The complication is that each index has its own parent-child relationships that have been implemented using the new [join](https://www.elastic.co/guide/en/elasticsearch/reference/5.6/parent-join.html) datatype. Some of the _should_ statements involve _has\_parent_ queries which work on the intended index but fail on the others because they lack the same relationships:
> query\_shard\_exception: [has\_child] join field [\_docJoin] doesn't hold [childEffort] as a child
One solution is to combine all of the parent-child relationships and use the same _join_ datatype across all indexes. This prevents the _has\_child_ query from failing but seems a bit confusing and hacky. Is there a cleaner solution to this problem?
Thanks,
Shane
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### Author:  [@mvg](https://discuss.elastic.co/u/mvg)
#### Post date: [October 27, 2017, 9:29am UTC](https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300/2 "2017-10-27T09:29:09Z")
You can try to use the multi search api and create a search request for each index with the correct `has_child` query. You do endup then with seperate search results.
You can also create a single search request with a `bool` query that old each `has_child` query as a should clause and use the `ignore_unmapped` parameter on the `has_child` query:
[https://www.elastic.co/guide/en/elasticsearch/reference/5.6/query-dsl-has-child-query.html#\_ignore\_unmapped](https://www.elastic.co/guide/en/elasticsearch/reference/5.6/query-dsl-has-child-query.html#_ignore_unmapped)
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### Author:  [@sclaggett](https://discuss.elastic.co/u/sclaggett)
#### Post date: [October 31, 2017, 5:47pm UTC](https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300/3 "2017-10-31T17:47:00Z")
Thank you Martijn, the `ignore_unmapped` field solved the problem!
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [November 28, 2017, 5:47pm UTC](https://discuss.elastic.co/t/how-to-query-multiple-indexes-in-elasticsearch-5-6-when-they-have-different-parent-child-mappings/105300/4 "2017-11-28T17:47:46Z")
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