How to divide two fields using InfluxDb query language

Question

I am using InfluxDB and I want to divide two fields.

My query which is picking result is working fine.

SELECT "payload-length" ,"in-data" FROM "test50"."autogen"."SYS-LOG" 

But when i try to divide these two fields i am getting error,

SELECT "payload-length"  / "in-data" FROM "test50"."autogen"."SYS-LOG" 

Error i am getting is :

unable to construct transform iterator from *influxql.stringChanIterator and *influxql.stringChanIterator

Not sure what i am missing.

Answer 1

What is the datatype stored in your fields ? What should the result represent ?

I get the same result if I try to do a division on two string fields.

> insert mymeasurement,tag1=tag1,tag2=tag2 fieldA="aaa",fieldB="bbb"
> insert mymeasurement,tag1=tag1,tag2=tag2 field1=500,field2=20

> select * from mymeasurement;
name: mymeasurement
time                field1 field2 fieldA fieldB tag1 tag2
----                ------ ------ ------ ------ ---- ----
1505944438559106045               aaa    bbb    tag1 tag2
1505944483558339332 500    20                   tag1 tag2

> show field keys from "mymeasurement"
name: mymeasurement
fieldKey fieldType
-------- ---------
field1   float
field2   float
fieldA   string
fieldB   string

> select field1 / field2 from mymeasurement
name: mymeasurement
time                field1_field2
----                -------------
1505944483558339332 25

> select fieldA , fieldB from mymeasurement
name: mymeasurement
time                fieldA fieldB
----                ------ ------
1505944438559106045 aaa    bbb

> select fieldA / fieldB from mymeasurement
ERR: unable to construct transform iterator from *influxql.stringChanIterator and *influxql.stringChanIterator