# Mutate add\_field value null

**URL:** <https://discuss.elastic.co/t/mutate-add-field-value-null/42296>\
**Category:** Logstash\
**Created:** [February 20, 2016, 9:18am UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296 "2016-02-20T09:18:59Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![rss87](https://avatars.discourse-cdn.com/v4/letter/r/b19c9b/32.png) [@rss87](https://discuss.elastic.co/u/rss87)\
**Post date:** [February 20, 2016, 9:18am UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296/1 "2016-02-20T09:18:59Z")

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Hi,

Is possible to add a field with value null, for example something like this:  
Mutate{ add\_field{"field1"=\> null}}

I tried this, but added null like a string

Thanks!!

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<div class="post-metadata">

**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [February 22, 2016, 7:01pm UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296/2 "2016-02-22T19:01:12Z")

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I suspect you need to use a ruby filter.

```
ruby { code => "event['nullfield'] = nil" }
```

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**Author:** ![sheilj](https://avatars.discourse-cdn.com/v4/letter/s/aca169/32.png) [@sheilj](https://discuss.elastic.co/u/sheilj)\
**Post date:** [November 17, 2016, 10:51am UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296/3 "2016-11-17T10:51:17Z")

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Hi,

I tried using this in my code as mentioned below:

mutate{ rename=\>{"add\_user\_name" =\> "userName"}}  
if[userName] {  
add\_field=\>{"assignedBy"=\> "%{userName}"}}  
add\_field=\>{"createdBy"=\> "%{userName}"} }  
}  
else{  
ruby { code =\> "event['assignedBy'] = nil" }   
ruby { code =\> "event['createdBy'] = nil" }  
}

But the data load from database is failing after this addition. (Only 3 rows are loaded out of some 70k rows). Kindly suggest. What am I missing here?

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<div class="post-metadata">

**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [November 17, 2016, 12:01pm UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296/4 "2016-11-17T12:01:44Z")

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@sheilj, please start a new thread for your unrelated question.

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 4:30am UTC](https://discuss.elastic.co/t/mutate-add-field-value-null/42296/5 "2017-07-06T04:30:25Z")

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