# How do are check existing fields, if doesnt exists add field

**URL:** <https://discuss.elastic.co/t/how-do-are-check-existing-fields-if-doesnt-exists-add-field/48148>\
**Category:** Logstash\
**Created:** [April 22, 2016, 8:56am UTC](https://discuss.elastic.co/t/how-do-are-check-existing-fields-if-doesnt-exists-add-field/48148 "2016-04-22T08:56:33Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![KabeloShongwe](https://avatars.discourse-cdn.com/v4/letter/k/7ba0ec/32.png) [@KabeloShongwe](https://discuss.elastic.co/u/KabeloShongwe)\
**Post date:** [April 22, 2016, 8:56am UTC](https://discuss.elastic.co/t/how-do-are-check-existing-fields-if-doesnt-exists-add-field/48148/1 "2016-04-22T08:56:33Z")

</div>

I'm indexing cisco logs, were some fileds dont exists in other events. please help.

---

<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:** [April 24, 2016, 4:10pm UTC](https://discuss.elastic.co/t/how-do-are-check-existing-fields-if-doesnt-exists-add-field/48148/2 "2016-04-24T16:10:32Z")

</div>

It's very hard to understand what you're asking. Please clarify. Examples of what you want to do often helps.

---

<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, 5:00am UTC](https://discuss.elastic.co/t/how-do-are-check-existing-fields-if-doesnt-exists-add-field/48148/3 "2017-07-06T05:00:58Z")

</div>