# In Elastic search, can we change the names of retrieved fields of searched response dynamically, like mongoDB projection?
**URL:** https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599
**Category:** Elasticsearch
**Created:** [April 24, 2023, 6:06am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599 "2023-04-24T06:06:20Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@cvam199](https://discuss.elastic.co/u/cvam199)
#### Post date: [April 24, 2023, 6:06am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599/1 "2023-04-24T06:06:20Z")
When I query on Elasticsearch (ES) to get some data, I get it in following format:
Response:
```auto
"hits" : [
{
"_index" : "testpoc",
"_type" : "_doc",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"ext" : [
{
"sii" : {
"1" : {
"csp" : 19.0
}
}
}
],
"pld" : "PDyfJ3MypQYK4MA2222",
"tms" : "2022-11-29T11:15:02+0000"
}
}]
```
Current query:
```auto
GET testpoc/_search
{
"_source": [
"tms",
"pld",
"ext.sii.1.csp"
]
}
```
I want to receive response in a particular format, rather than getting "ext[0].sii.1.csp", I want to map it into "csp" field.
Note: "ext[0].sii.1.csp" is dynamic, I can query to get some "ext[0].sii.1.xyz", and I want to receive it as "xyz" field name. Requirement is somewhat similar to "projection" functionality of mongoDB (i.e. include-\>as method).
Desired response:
```auto
"hits" : [
{
"_index" : "testpoc",
"_type" : "_doc",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"csp" : 19.0,
"pld" : "PDyfJ3MypQYK4MA2222",
"tms" : "2022-11-29T11:15:02+0000"
}
}]
```
What should I add in query or search request to get the required response?
I read about the aliasing in ES, but for that I've to change the index mapping (in my project it's not an option), I did try ES scripts also, but it is somewhat similar to processing the response in java code that can be done on project side too.
I want to know if there is anything that can be used to map or change the retrieved fields names of ES search response?
---
### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [April 24, 2023, 6:12am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599/2 "2023-04-24T06:12:09Z")
Elasticsearch will return the JSON stored (or selected fields) but I do not think there is any built in support for rewriting data. This is as far as I know something you need to handle client side.
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [April 24, 2023, 6:27am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599/3 "2023-04-24T06:27:01Z")
Christian is correct, there's no way to do this in Elasticsearch.
---
### Author:  [@cvam199](https://discuss.elastic.co/u/cvam199)
#### Post date: [April 24, 2023, 6:42am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599/4 "2023-04-24T06:42:21Z")
Thanks @Christian_Dahlqvist @warkolm. I will make the required changes in client side.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [May 22, 2023, 6:43am UTC](https://discuss.elastic.co/t/in-elastic-search-can-we-change-the-names-of-retrieved-fields-of-searched-response-dynamically-like-mongodb-projection/330599/5 "2023-05-22T06:43:17Z")
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