# Cannot convert created field to integer
**URL:** https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005
**Category:** Logstash
**Created:** [March 7, 2022, 6:45pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005 "2022-03-07T18:45:38Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@aerodynamic](https://discuss.elastic.co/u/aerodynamic)
#### Post date: [March 7, 2022, 6:45pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/1 "2022-03-07T18:45:38Z")
Currently I'm dealing with a situation where a field name is dynamically created and needs to be set to an integer like so
```auto
mutate {
add_field => {
"%{fieldName}" => "%{dataInteger}"
}
convert => { "%{fieldName}" => "integer" }
}
```
This conversion does not affect fieldName.
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [March 7, 2022, 6:58pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/2 "2022-03-07T18:58:31Z")
mutate does operations in a [specific order](https://www.elastic.co/guide/en/logstash/current/plugins-filters-mutate.html#plugins-filters-mutate-proc_order), and the common options like add\_field come [after that](https://github.com/elastic/logstash/blob/0887d7609df9ba72a5d0cd003c639b16da198622/logstash-core/lib/logstash/filters/base.rb#L197). Thus [fieldName] is not created until after the convert, and convert of a non-existent field is a no-op. Split it into two mutate filters.
---
### Author:  [@aerodynamic](https://discuss.elastic.co/u/aerodynamic)
#### Post date: [March 7, 2022, 7:13pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/3 "2022-03-07T19:13:44Z")
Hello @Badger
Thanks for the response!
We have tried
```auto
mutate {
add_field => {
"%{fieldName}" => "%{dataInteger}"
}
}
mutate {
convert => { "%{fieldName}" => "integer" }
}
```
But it still doesn't function
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [March 7, 2022, 7:46pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/4 "2022-03-07T19:46:48Z")
I suspect what you want is
```
mutate { add_field => { "fieldName" => "%{dataInteger}" } }
mutate { convert => { "fieldName" => "integer" } }
```
---
### Author:  [@aerodynamic](https://discuss.elastic.co/u/aerodynamic)
#### Post date: [March 7, 2022, 8:15pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/5 "2022-03-07T20:15:04Z")
To be clear.
fieldName is the name of a variable who's value is the actual field name.
Like at some point
```auto
fieldName => "cookieCount"
```
Does that make sense?
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [March 7, 2022, 8:45pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/6 "2022-03-07T20:45:17Z")
> [@aerodynamic](#):
>
> fieldName is the name of a variable who's value is the actual field name.
That will work for the add\_field because the [decorator calls sprintf](https://github.com/elastic/logstash/blob/0887d7609df9ba72a5d0cd003c639b16da198622/logstash-core/lib/logstash/util/decorators.rb#L31) on the fieldname. The convert function just does a [get](https://github.com/logstash-plugins/logstash-filter-mutate/blob/d45bfb7211fc0a11afd7dc917cefa295752cc63d/lib/logstash/filters/mutate.rb#L308) of the field. Since it does not sprintf you cannot use %{} in the convert.
You would have to use a ruby filter to do it. The following
```
input { generator { count => 1 lines => [''] } }
filter {
mutate { add_field => { "fieldName" => "foo" "foo" => "1" } }
ruby {
code => '
name = event.get("fieldName")
event.set(name, event.get(name).to_i)
'
}
}
output { stdout { codec => rubydebug { metadata => false } } }
```
will produce
```
"foo" => 1
```
---
### Author:  [@aerodynamic](https://discuss.elastic.co/u/aerodynamic)
#### Post date: [March 7, 2022, 10:00pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/7 "2022-03-07T22:00:25Z")
Thank you for the reply and explanation!
I will try ASAP
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [April 4, 2022, 10:00pm UTC](https://discuss.elastic.co/t/cannot-convert-created-field-to-integer/299005/8 "2022-04-04T22:00:36Z")
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