InfluxDB 1.8 - SELECT exact - influxdb

Question

I'm trying to discern if it is possible to query InfluxDB to have an exact match on tags without having to first query InfluxDB for the TAG KEYS to generate my query.
Here is an example to showcase what I'm trying to accomplish,
Connected to http://localhost:8086 version 1.10.0
InfluxDB shell version: 1.10.0
> create database so
> use so
Using database so
> INSERT cpu,cpu=cpu0,env=intg,host=is-nflxts101t time_system=13592
> INSERT cpu,env=intg,host=is-nflxts101t time_system=134
SELECT * FROM cpu
name: cpu
time cpu env host time_system
---- --- --- ---- -----------
1668608108642977000 cpu0 intg is-nflxts101t 13592
1668608113752018000 intg is-nflxts101t 134 # <--- We want to get this line ONLY
The goal is to get the final line where cpu isn't specified.
The naive query gives us the complete set of rows, including the one we do not want,
> SELECT * FROM cpu WHERE "env"='intg' AND "host"='is-nflxts101t'
name: cpu
time cpu env host time_system
---- --- --- ---- -----------
1668608108642977000 cpu0 intg is-nflxts101t 13592 # <--- undesired
1668608113752018000 intg is-nflxts101t 134
and while I could first fetch all TAG KEYS to programatically generate the query,
> SELECT * FROM cpu WHERE "env"='intg' AND "host"='is-nflxts101t' AND "cpu" = ''
name: cpu
time cpu env host time_system
---- --- --- ---- -----------
1668608113752018000 intg is-nflxts101t 134
in my application code I was hoping there was/is a way to express this psuedo-query,
> SELECT * FROM cpu WHERE EXACT "env"='intg' AND "host"='is-nflxts101t'
name: cpu
time cpu env host time_system
---- --- --- ---- -----------
1668608113752018000 intg is-nflxts101t 134
Is there any way to accomplish this? Or am I stuck with fetching the keys first?

Answer 1

Your sample should be good enough to filter out null-value tag with other conditions:
SELECT * FROM cpu WHERE "env"='intg' AND "host"='is-nflxts101t' AND "cpu" = ''
as for tags, doing WHERE some_tag = '' will match rows for which the tag has no value. (The tag value will still be returned as null in the response, though, not as the empty string, because internally-consistent type systems are for pansies.)