# Copy field value to a new field in existing index

**URL:** <https://discuss.elastic.co/t/copy-field-value-to-a-new-field-in-existing-index/224595>\
**Category:** Elasticsearch\
**Created:** [March 23, 2020, 5:58am UTC](https://discuss.elastic.co/t/copy-field-value-to-a-new-field-in-existing-index/224595 "2020-03-23T05:58:21Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [March 23, 2020, 8:16am UTC](https://discuss.elastic.co/t/copy-field-value-to-a-new-field-in-existing-index/224595/2 "2020-03-23T08:16:45Z")

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Could you provide a full recreation script as described in [About the Elasticsearch category](https://discuss.elastic.co/t/about-the-elasticsearch-category/21). It will help to better understand what you are doing. Please, try to keep the example as simple as possible.

A full reproduction script will help readers to understand, reproduce and if needed fix your problem. It will also most likely help to get a faster answer.

Without that it's hard to know but let's make some guesses. May be the type is actually `_doc` and not `test`.  
You can look also at the rename processor and the reindex API. So you reindex in a new clean index instead of keeping the old mapping around.

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_[View the full topic](https://discuss.elastic.co/t/copy-field-value-to-a-new-field-in-existing-index/224595)._