# Need to return part of a doc from a search query/filter; is parent-child the way to go? **URL:** \ **Category:** Elasticsearch\ **Created:** [November 1, 2016, 5:19am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514 "2016-11-01T05:19:07Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![PAK90](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@PAK90](https://discuss.elastic.co/u/PAK90)\ **Post date:** [November 1, 2016, 5:19am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/1 "2016-11-01T05:19:07Z")
I have a set of docs (let's call them books), which have a subset of information (let's say editions), for a data structure somewhat akin to this: ``` "book": { "author": "A. N. Author", "title": "Fantastic Queries and How to Index Them" "editions": [ { "publisher":"penguin", "isbn": 124161256653, "coverArtist":"Pain T Brush", "amazonPrice":65.50 }, { "publisher":"orbit", "isbn": 124163526653, "coverArtist":"Pain T Brush", "amazonPrice":25.99 }, { "publisher":"tor", "isbn": 124169876353, "coverArtist":"Pen See Il", "amazonPrice":700.00 } ] } ``` Right now with the queries I have (which search on `editions.publisher` or `editions.isbn`), I get the whole document back, including editions that don't match the query results (I believe this is what's known as flattened/normalized data structure?). So, to be clear, if I search `coverArtist` for Pain T Brush, the data I want returned is: ``` "book": { "author": "A. N. Author", "title": "Fantastic Queries and How to Index Them" "editions": [ { "publisher":"penguin", "isbn": 124161256653, "coverArtist":"Pain T Brush", "amazonPrice":65.50 }, { "publisher":"orbit", "isbn": 124163526653, "coverArtist":"Pain T Brush", "amazonPrice":25.99 } ] } ``` Same with the other queries. If I search for a specific `isbn`, I only want its data to come back. If I set a price range of `> 500`, I'd only want the last edition (along with the author and title information, of course). And finally, if I search for `Fantastic Queries and How to Index Them` in the title, I want the whole doc returned, with all edition information, since I didn't specify anything edition-specific. I was made aware of child and parent docs, in which each edition would be a child of one parent book. However, querying this system returns either a child or a parent, not both, which is what I need. Granted, if I get a child, its `_parent` property can be used to `GET` the parent's data, but that seems inefficient (i.e. I have to get two separate docs with two separate `GET` requests; first the child result, then its parent). So really, I wanted to double check here that I'm not missing some obvious solution. Is this parent-child doc structure the only way to achieve what I need, or is there something else I can use? ---
**Author:** ![xavierfacq](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/xavierfacq/32/8744_2.png) [@xavierfacq](https://discuss.elastic.co/u/xavierfacq)\ **Post date:** [November 1, 2016, 7:47am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/2 "2016-11-01T07:47:32Z")
Hi, Keeping exactly the same structure and what you want to do in the search, you can use the Nested functionnality. [https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-nested-query.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-nested-query.html) Add in your mapping, for the field "editions" ``` "type" : "nested" ``` It's a little bit "harder" to understand, but you will have documents (book) matching your query AND, nested sub-elements (editions) matching the query. Bye, Xavier ---
**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\ **Post date:** [November 1, 2016, 7:52am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/3 "2016-11-01T07:52:42Z")
Yes. Use nested docs and have a look at [https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-inner-hits.html#nested-inner-hits](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-inner-hits.html#nested-inner-hits) ---
**Author:** ![PAK90](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@PAK90](https://discuss.elastic.co/u/PAK90)\ **Post date:** [November 1, 2016, 4:35pm UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/4 "2016-11-01T16:35:34Z")
To clarify, right now my mapping for `editions` looks something like this: ``` editions: { properties: { coverArtist: stringWithRaw, isbn: {type: "integer"}, publisher: stringWithRaw, amazonPrice: {type: "double"}, } } ``` where `stringWithRaw` is simply ``` let stringWithRaw = { type:"string", fields:{ "raw":{type:"string", index:"not_analyzed"} } }; ``` So all I have to do is to add `type: "nested"` above where I declare the properties of `editions`? ---
**Author:** ![xavierfacq](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/xavierfacq/32/8744_2.png) [@xavierfacq](https://discuss.elastic.co/u/xavierfacq)\ **Post date:** [November 1, 2016, 5:29pm UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/5 "2016-11-01T17:29:39Z")
Yes like that : ``` editions: { "type": "nested", properties: { coverArtist: stringWithRaw, isbn: {type: "integer"}, publisher: stringWithRaw, amazonPrice: {type: "double"}, } } ``` ---
**Author:** ![PAK90](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@PAK90](https://discuss.elastic.co/u/PAK90)\ **Post date:** [November 2, 2016, 12:25am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/6 "2016-11-02T00:25:42Z")
My initial testing is showing that I still get the `editions` that don't match the query... this is the query I'm testing with: ``` GET books/_search { "query": { "nested" : { "path" : "editions", "query" : { "bool" : { "must" : [ { "match" : {"editions.coverArtist" : "Pain T Brush"} } ] } } } } } ``` But I still get resulting `book` objects that contain `edition` objects with the other artist (`Pen See Il`) in the hits results. EDIT: I should clarify; in the `hits` array that is returned, I want the `_source` that's returned to have its `editions` array trimmed/modified/filtered to only include the `editions` that match the query. Not sure if the nesting is capable of accomplishing this; not sure if it can modify the returned `_source`. I have a followup question; can I do partial word matching in nested queries? The field that I'm using nested queries on now used to be using `QueryString`, which I'm guessing is not going to work with nested. However, I'd really like to have partial word matching (i.e. returning all docs with `coverArtist: "Pain T Br"` should return the same as when searching with full name). ---
**Author:** ![xavierfacq](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/xavierfacq/32/8744_2.png) [@xavierfacq](https://discuss.elastic.co/u/xavierfacq)\ **Post date:** [November 2, 2016, 8:32am UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/7 "2016-11-02T08:32:44Z")
You should have your documents in the "hits" array with all editions attached, that's the main documents array, returned fulfilled. In a second part of the results you should find the "inner\_hits" arrays that contains ONLY nested documents matching your query. For your new question, it depends on what you want to allow as query, a good start point is to add this param : ``` "minimum_should_match" : "75%" ``` @see [https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-minimum-should-match.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-minimum-should-match.html) ---
**Author:** ![PAK90](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@PAK90](https://discuss.elastic.co/u/PAK90)\ **Post date:** [November 2, 2016, 7:07pm UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/8 "2016-11-02T19:07:57Z")
I see now, all the relevant info is stored in `inner_hits`. It's a bit annoying that it's separate from the usual `_source` data I use, but I can work with that. What I allow is query is partial word searches, since I have a simple text input field that searches as people type. Can I not use some type of `prefix` matching? For example, I've used `multi_match` with `type: "phrase_prefix"` before, will that work with nested docs (or something like `match_phrase_prefix`)? ---
**Author:** ![xavierfacq](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/xavierfacq/32/8744_2.png) [@xavierfacq](https://discuss.elastic.co/u/xavierfacq)\ **Post date:** [November 2, 2016, 8:24pm UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/9 "2016-11-02T20:24:28Z")
> [@PAK90](#): > > I see now, all the relevant info is stored in inner\_hits. It's a bit annoying that it's separate from the usual \_source data I use, but I can work with that. That's good ! You can mark this post as resolved and open a new one with the query you want to do. Note that: all queries as possible within the nested. Boolean, multi\_match, etc... no limit ! ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:07pm UTC](https://discuss.elastic.co/t/need-to-return-part-of-a-doc-from-a-search-query-filter-is-parent-child-the-way-to-go/64514/10 "2017-07-05T22:07:11Z")