# Mutate filter unable to convert date to string **URL:** \ **Category:** Logstash\ **Created:** [August 1, 2018, 9:13am UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518 "2018-08-01T09:13:02Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![ravian100](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ravian100/32/33941_2.png) [@ravian100](https://discuss.elastic.co/u/ravian100)\ **Post date:** [August 1, 2018, 9:13am UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/1 "2018-08-01T09:13:02Z")
I have searched a lot regarding this issue and now I am posting this problem. here is my configuration file. input { file { path =\> "/home/Kunden2.csv" start\_position =\> "beginning" sincedb\_path =\> "/dev/null" } } filter { csv { separator =\> "," columns =\> [ "Kunden\_Id", "Kunden\_Gueltig\_Ab", "Kunden\_geultig\_Bis", "Kunden\_Vorname", "Kunden\_Nachname", "Kundenname", "Kunden\_Othername", "Kundenanschrift, Strasse und Hausnummer", "Kundenanschrift Postleitzahl", "Kunden\_Telephon", "Kunden\_Fax", "Kundenanschrift Ort", "Kunden\_Arzt\_Type", "Kunden\_Gpid", "IK-NR.: = Instituationskennzeichen", "Instituationskennzeichen\_Activeab", "Instituationskennzeichen\_Activebis" ] } mutate { convert =\> { "Kunden\_Gueltig\_Ab"=\> "string" "Kunden\_geultig\_Bis"=\> "string" "Instituationskennzeichen\_Activeab"=\> "string" "Instituationskennzeichen\_Activebis" =\> "string" } } } output { elasticsearch { hosts =\> "[http://localhost:9200](http://localhost:9200)" index =\> "Kunden\_lexica2" } stdout {} } I am trying to convert date into string using logstash configuration files. Data loads successfully but the data type is not changing. I know the other way [map date type manually] like PUT temp\_index2 { "mappings": { "doc": { "properties": { "Kunden\_Id": { "type": "text" }, "Kunden\_Gueltig\_Ab": { "type": "text" }, "Kunden\_geultig\_Bis": { "type": "text" }, "Kunden\_Vorname": { "type": "text" }, "Kunden\_Nachname": { "type": "text" }, "Kundenname": { "type": "text" }, "Kunden\_Othername": { "type": "text" }, "Kundenanschrift, Strasse und Hausnummer": { "type": "text" }, "Kundenanschrift Postleitzahl": { "type": "text" }, "Kunden\_Telephon": { "type": "text" }, "Kunden\_Fax": { "type": "text" }, "Kundenanschrift Ort": { "type": "text" }, "Kunden\_Arzt\_Type": { "type": "text" }, "Kunden\_Gpid": { "type": "text" }, "IK-NR.: = Instituationskennzeichen": { "type": "text" }, "Instituationskennzeichen\_Activeab": { "type": "text" }, "Instituationskennzeichen\_Activebis": { "type": "text" } } } } } Kindly help me out, I want to do it by first method. Thank you in advance ---
**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:** [August 1, 2018, 9:39am UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/2 "2018-08-01T09:39:05Z")
Have you reindexed the data? Changing the data type in Logstash won't affect the mappings of an existing ES index. ---
**Author:** ![ravian100](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ravian100/32/33941_2.png) [@ravian100](https://discuss.elastic.co/u/ravian100)\ **Post date:** [August 1, 2018, 9:47am UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/3 "2018-08-01T09:47:08Z")
Thank you for answer. By creating manual index and then re-indexing works. But what about through logstash as I mentioned in my problem statement? I want to change data type before loading the data ---
**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:** [August 1, 2018, 11:19am UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/4 "2018-08-01T11:19:31Z")
You can certainly change the data type of a field in a Logstash event (and doing so will affect ES's auto-detection of field types), but nothing you do in Logstash can change the mappings of an existing ES index. If ES incorrectly detects a string as a date there's nothing Logstash can do to avoid that. ---
**Author:** ![ravian100](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ravian100/32/33941_2.png) [@ravian100](https://discuss.elastic.co/u/ravian100)\ **Post date:** [August 6, 2018, 3:23pm UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/5 "2018-08-06T15:23:12Z")
@magnusbaeck Can you please elaborate your answer with the help of some example i-e in my case, mentioned above in the question area. That would be great for understanding purpose. ---
**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:** [August 6, 2018, 5:47pm UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/6 "2018-08-06T17:47:38Z")
I don't understand what you're asking. You already know how to use the mutate filter to convert the data type of a field in Logstash and you know how to use the put mapping API to explicitly set the mappings of a field. What is still unclear? ---
**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\ **Post date:** [August 6, 2018, 6:33pm UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/7 "2018-08-06T18:33:05Z")
If logstash sends a field that does not exist in the index with a string value such as "2018-08-06T17:18:50.558Z" to elasticsearch, then unless there is a template that tells it not to, elasticsearch will convert that to a date. You cannot change that behaviour in logstash. So you can use a template, or you can force the field to exist as a string by ingesting a dummy record that does not look like a date. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [September 3, 2018, 6:33pm UTC](https://discuss.elastic.co/t/mutate-filter-unable-to-convert-date-to-string/142518/8 "2018-09-03T18:33:23Z")
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