# Unsupported mean iterator type query.stringInterruptIterator

**URL:** <https://community.influxdata.com/t/unsupported-mean-iterator-type-query-stringinterruptiterator/6264>\
**Category:** Systems\
**Created:** [August 16, 2018, 3:30pm UTC](https://community.influxdata.com/t/unsupported-mean-iterator-type-query-stringinterruptiterator/6264 "2018-08-16T15:30:16Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bob\_monty](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/bob_monty/32/248_2.png) [@bob\_monty](https://community.influxdata.com/u/bob_monty)\
**Post date:** [August 16, 2018, 3:30pm UTC](https://community.influxdata.com/t/unsupported-mean-iterator-type-query-stringinterruptiterator/6264/1 "2018-08-16T15:30:17Z")

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Greetings,  
Need some assistance. I imported a csv into influx. it uploaded successfully. i tagged 2 items called App and Server. Under App there are multiple Servers and there are also multiple Apps. I can query on Server and i see my graph. i can query on App and it aggregates all the Servers under that app and i can see data. If i try to query App then a Server under App i don’t get any data. Any idea why this is happening ? Also i tried chronograf to see the data, and when i try the same query App then a Server under App i get

\*unsupported mean iterator type: query.stringInterruptIterator

what am i doing wrong ?  
Thanks again.

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**Author:** ![mschae16](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/mschae16/32/1005_2.png) [@mschae16](https://community.influxdata.com/u/mschae16)\
**Post date:** [August 16, 2018, 6:13pm UTC](https://community.influxdata.com/t/unsupported-mean-iterator-type-query-stringinterruptiterator/6264/2 "2018-08-16T18:13:38Z")

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Any chance you could provide some examples or output of successful queries versus unsuccessful queries for this circumstance (to provide some context)? Thanks.

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<div class="post-metadata">

**Author:** ![Anto\_Tapia](https://avatars.discourse-cdn.com/v4/letter/a/d78d45/32.png) [@Anto\_Tapia](https://community.influxdata.com/u/Anto_Tapia)\
**Post date:** [January 27, 2019, 4:24am UTC](https://community.influxdata.com/t/unsupported-mean-iterator-type-query-stringinterruptiterator/6264/3 "2019-01-27T04:24:05Z")

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Hello,mschae16. I have the same problem. I’m using **Influxdb, Telegraf and Chronograf and Mqtt (CloudMqtt)**. My Mqtt receives data from an ESP32 as a String. So, I collect this data using telegraf but with a little change in the **[[inputs.mqtt\_consumer]]** plugin. Here are the changes:

**[[inputs.mqtt\_consumer]]**  
#data\_format =“influx”  
data\_format = “value”  
data\_type = “string”

Due to my data are all strings, I couldn’t save it into Influxdb because Influx expects the data to be a Line protocol. So making the changes I’ve mentioned above, I was able to store data in influx as a string.  
But when I try to see data in Chronograf it doesn’t work.  
Same error:

> [@bob\_monty](#):
>
> \*unsupported mean iterator type: query.stringInterruptIterator

I’m also using Grafana and at first (Query B default configuration) it was the same, I couldn’t see anything in the chart, using the **Query B** configuration:

 ![sshot-4](https://us1.discourse-cdn.com/flex023/uploads/influxdata/original/2X/d/d68ab0211150591deb580ce742cceb08d6febfa5.png)

Then I made some changes (Query A) and it works.  
_I’ve provided Query B just as an example of the default query._

**This is the query for chronograf:**  
SELECT mean(“value”) AS “mean\_value” FROM “mqttbase”.“autogen”.“mqtt\_consumer” WHERE time \> :dashboardTime: AND “topic”=‘temperatura’ GROUP BY time(:interval:) FILL(null)

Doesn’t work. I know it is because of my string data but I don’t know how to do the query in this case.

Could you help me, please?  
Thank you in advance,=)