How to use Distinct function in influxDB

Thanks for the extra info @Ammad.

Short Answer

Try GROUP BY with tags. DISTINCT() only works with fields.

Long Answer

distinct() works on fields, not tags. See here:

https://docs.influxdata.com/influxdb/v1.0/query_language/functions/#distinct

DISTINCT() returns the unique values of a single field.

The field values are meant to be the actual data you're interested in. Tag values are metadata: data about the data. Most functions in database systems operate on the data or the metadata, but rarely on both.

Here's a toy example on v0.13, showing that distinct() really doesn't work with tags:

insert foo,tag1=asdf field1="some text"
insert foo,tag1=asdf field1="some text"
insert foo,tag1=asdfg field1="some text"
insert foo,tag1=asdfg field1="some text"
insert foo,tag1=asdfg field1="some more text"
insert foo,tag1=asdfg field1="some more text"

Now some queries:

select * from foo

name: foo
time                            field1          tag1
2016-09-12T05:19:53.563221799Z  some text       asdf
2016-09-12T05:20:03.027652248Z  some text       asdf
2016-09-12T05:20:10.04939971Z   some text       asdfg
2016-09-12T05:20:11.235525548Z  some text       asdfg
2016-09-12T05:20:17.418920163Z  some more text  asdfg
2016-09-12T05:20:19.354742922Z  some more text  asdfg

Now let's try distinct()

select distinct(tag1) from foo

Results in no output at all.

select distinct(field1) from foo

name: foo
time                    distinct
1970-01-01T00:00:00Z    some text
1970-01-01T00:00:00Z    some more text

You might be able to get what you want by using GROUP BY. Like this:

select distinct(field1) from foo group by tag1

Which gives:

name: foo
tags: tag1=asdf
time                    distinct
1970-01-01T00:00:00Z    some text

name: foo
tags: tag1=asdfg
time                    distinct
1970-01-01T00:00:00Z    some text
1970-01-01T00:00:00Z    some more text

This shows each value of tag1, and the values of field1 associated with that tag1 value.

Hope that helps.

There is SHOW TAG VALUES WITH key = path that one can use to get unique Tag values