# How to \_update a non existing field
**URL:** https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349
**Category:** Elasticsearch
**Created:** [April 16, 2012, 1:46pm UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349 "2012-04-16T13:46:31Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Andy\_Wick](https://discuss.elastic.co/u/Andy_Wick)
#### Post date: [April 16, 2012, 1:46pm UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349/1 "2012-04-16T13:46:31Z")
Using ElasticSearch as a DB I'm looking for a way to \_update a field that
doesn't exist. I don't want to set the field to 0 when first indexed
because I don't know the field names for other reasons. I assume I can't
use null\_value in mapping either, since I don't know the field name BEFORE
I index the document, and setting the null\_value afterwards I assume won't
help.
curl '[http://localhost:9200/tests/test/test1?pretty](http://localhost:9200/tests/test/test1?pretty)' -d ' { }'
curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
{"script": "ctx.\_source.b += v", "params": {"v": 2}}'
Returns ElasticSearchIllegalArgumentException[failed to execute script];
nested: PropertyAccessException[[Error: could not access: b; in class:
java.util.LinkedHashMap]\n[Near : {... ctx.\_source.b+v ....}]
I tried using isdef, but that seems to always return false, I'm probably
using it wrong.
curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
{"script": "if (isdef ctx.\_source.b) {ctx.\_source.b += v} else
{ctx.\_source.b = v}", "params": {"v": 2}}'
---
### Author:  [@kimchy](https://discuss.elastic.co/u/kimchy)
#### Post date: [April 17, 2012, 1:03pm UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349/2 "2012-04-17T13:03:27Z")
Try and check if \_ctx.\_source.b is null or not
On Mon, Apr 16, 2012 at 4:46 PM, Andy Wick [andywick@gmail.com](mailto:andywick@gmail.com) wrote:
> Using Elasticsearch as a DB I'm looking for a way to \_update a field that
> doesn't exist. I don't want to set the field to 0 when first indexed
> because I don't know the field names for other reasons. I assume I can't
> use null\_value in mapping either, since I don't know the field name BEFORE
> I index the document, and setting the null\_value afterwards I assume won't
> help.
>
> curl '[http://localhost:9200/tests/test/test1?pretty](http://localhost:9200/tests/test/test1?pretty)' -d ' { }'
>
> curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
> {"script": "ctx.\_source.b += v", "params": {"v": 2}}'
>
> Returns ElasticSearchIllegalArgumentException[failed to execute script];
> nested: PropertyAccessException[[Error: could not access: b; in class:
> java.util.LinkedHashMap]\n[Near : {... ctx.\_source.b+v ....}]
>
> I tried using isdef, but that seems to always return false, I'm probably
> using it wrong.
>
> curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
> {"script": "if (isdef ctx.\_source.b) {ctx.\_source.b += v} else
> {ctx.\_source.b = v}", "params": {"v": 2}}'
---
### Author:  [@Andy\_Wick](https://discuss.elastic.co/u/Andy_Wick)
#### Post date: [April 18, 2012, 12:45am UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349/3 "2012-04-18T00:45:32Z")
Like this? I tried both ctx.\_source.b and \_ctx.\_source.b with the same
result.
curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
{"script": "if (ctx.\_source.b == null) {ctx.\_source.b += v} else
{ctx.\_source.b = v}", "params": {"v": 2}}'
{
"error" :
"RemoteTransportException[[moloches-mtc04][inet[/172.29.127.44:9300]][update]];
nested: ElasticSearchIllegalArgumentException[failed to execute script];
nested: PropertyAccessException[[Error: could not access: b; in class:
java.util.LinkedHashMap]\n[Near : {... ctx.\_source.b+v ....}]\n
^\n[Line: 1, Column: 1]]; ",
---
### Author:  [@kimchy](https://discuss.elastic.co/u/kimchy)
#### Post date: [April 19, 2012, 2:32pm UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349/4 "2012-04-19T14:32:29Z")
Heya, this seems to work:
curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '{"script":
"if (ctx.\_source.containsKey("b")) {ctx.\_source.b += v} else
{ctx.\_source.b = v}", "params": {"v": 2}}'
(notes, I used " to escape it the "b" key, you won't need to do it if you
don't use curl).
On Wed, Apr 18, 2012 at 3:45 AM, Andy Wick [andywick@gmail.com](mailto:andywick@gmail.com) wrote:
> Like this? I tried both ctx.\_source.b and \_ctx.\_source.b with the same
> result.
>
> curl '[http://localhost:9200/tests/test/test1/\_update?pretty](http://localhost:9200/tests/test/test1/_update?pretty)' -d '
> {"script": "if (ctx.\_source.b == null) {ctx.\_source.b += v} else
> {ctx.\_source.b = v}", "params": {"v": 2}}'
>
> {
> "error" :
> "RemoteTransportException[[moloches-mtc04][inet[/172.29.127.44:9300]][update]];
> nested: ElasticSearchIllegalArgumentException[failed to execute script];
> nested: PropertyAccessException[[Error: could not access: b; in class:
> java.util.LinkedHashMap]\n[Near : {... ctx.\_source.b+v ....}]\n
> ^\n[Line: 1, Column: 1]]; ",
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 3:31am UTC](https://discuss.elastic.co/t/how-to--update-a-non-existing-field/7349/5 "2017-07-06T03:31:57Z")