My database certainly has some points that I want. It complains that cost is a string (introduced via an old json interface) if I try to sum the data it gives:
ERR: unsupported sum iterator type: *influxql.stringInterruptIterator
I guess I'm trying to sum a string?
> SELECT "cost" from watts order by desc limit 10
name: watts
time cost
---- ----
2022-09-26T10:16:45.925068962Z 0.0345
2022-09-26T10:13:33.290878925Z 0.0345
2022-09-26T10:11:22.681558454Z 0.0345
2022-09-26T10:07:09.405004296Z 0.0345
2022-09-26T10:05:42.859464731Z 0.0345
2022-09-26T10:03:35.006380011Z 0.0345
2022-09-26T10:02:54.010176738Z 0.0345
2022-09-26T10:00:21.790285285Z 0.0345
2022-09-26T09:59:21.177746381Z 0.0345
2022-09-26T09:58:31.31611238Z 0.0345
So, following influxdb doc, I've cast to float and this query below doesn't give any errors, but no results either. This must be something really simple, mustn't it? I actually want to get a version of this query into Grafana, currently giving the dreaded No Data Points.
> SELECT sum("cost"::float) FROM "watts" WHERE time >= 1664146800000ms GROUP BY time(5m)
I assume you are using InfluxDB v1. InfluxDB does support some cast operations but it doesn't support cast String values to Float values. See more detail here.
You could rewrite your date with correct data type. That is, instead of writing the cost as String:
INSERT watts cost="0.0345"
Try to write it as Float (note: remove the double quotes):
INSERT watts cost=0.0345
Then you can run the sum happily:
select sum(cost) from watts
Related
I created a continuous query to downsample readings from temperature sensors in my influxdb to store hourly means for a longer time. There are readings of multiple sensors in one table. Upon executing the query, the sensors ip is missing.
Basic data looks like this:
> SELECT ip,tC FROM ht LIMIT 5
name: ht
time ip tC
---- -- --
1671057540000000000 192.168.0.83 21
1671057570000000000 192.168.0.83 21
1671057750000000000 192.168.0.17 21.38
The continuous query (simplified without CREATE ... END):
SELECT last(ip), mean("tC") AS "mean_temp" INTO "downsampled"."ht_downsampled" FROM "ht" GROUP BY time(1h),ip
The issue is, the value of 'ip' is only a tag, not the value in the table and subsequently is missing in the table the query inserts into:
name: ht
tags: ip=192.168.0.17
time ip mean_temp mean_hum
---- -- --------- --------
1671055200000000000 21.47 42.75
1671058800000000000 21.39428571428571 48.785714285714285
1671062400000000000 21.314999999999998 51.625
Why is last(ip) not producing any value?
Can I get the value from the 'tags' into the table?
Is there a different approach to group data with a constant value?
Could you just try query the ip instead of the last(ip) since you are grouping by the ip in the statement already?
Sample code:
SELECT ip, mean("tC") AS "mean_temp" INTO "downsampled"."ht_downsampled" FROM "ht" GROUP BY time(1h), ip
I am trying to write a where clause on InfluxDB where the points are filtered via their key values.
My points have the field ping_to_google.com and the tag key user where user can be raspi-2 or raspi-5. This is a sample output of the database:
> select * from networks where time > now()-1h
name: networks
time ping_to_google.com user
---- ------------------ ----
1645494054000000000 3.528 raspi-2
1645494078000000000 3.578 raspi-2
I am using InfluxDB version 1.8 and InfluxDB shell version 1.6.4
This query will work!
select * from networks where time > now()-1h AND "user"='raspi-2'
According to the documentation of the influxDB you should only single qoute tag values:
Tags
tag_key <operator> ['tag_value']
Single quote tag values in the WHERE clause. Queries with unquoted tag values or double quoted tag values will not return any data and, in most cases, will not return an error.
They don't specify how to write tag keys. It is crazy that the database does not produce any errors in most cases. Also, it's not clear (and very unexpected after reading this documentation) that the tag key should be double-qouted. But this works and is how to do it!
I'd like to calculate the delta values for a series of measurements stored in an InfluxDB. The values are readings from an electricity meter taken every 5 minutes. The values increase over time. Here is subset of the data to give you an idea (commands shown below are executed in the InfluxDB CLI):
> SELECT "Haushaltstromzaehler - cnt" FROM "myhome_measurements" WHERE time >= '2018-02-02T10:00:00Z' AND time < '2018-02-02T11:00:00Z'
name: myhome_measurements
time Haushaltstromzaehler - cnt
---- --------------------------
2018-02-02T10:00:12.610811904Z 11725.638
2018-02-02T10:05:11.242021888Z 11725.673
2018-02-02T10:10:10.689827072Z 11725.707
2018-02-02T10:15:12.143326976Z 11725.736
2018-02-02T10:20:10.753357056Z 11725.768
2018-02-02T10:25:11.18448512Z 11725.803
2018-02-02T10:30:12.922032896Z 11725.837
2018-02-02T10:35:10.618788096Z 11725.867
2018-02-02T10:40:11.820355072Z 11725.9
2018-02-02T10:45:11.634203904Z 11725.928
2018-02-02T10:50:11.10436096Z 11725.95
2018-02-02T10:55:10.753853952Z 11725.973
Calculating the differences in the InfluxDB CLI is pretty straightforward with the difference() function. This gives me the electricity consumed within the 5 minutes intervals:
> SELECT difference("Haushaltstromzaehler - cnt") FROM "myhome_measurements" WHERE time >= '2018-02-02T10:00:00Z' AND time < '2018-02-02T11:00:00Z'
name: myhome_measurements
time difference
---- ----------
2018-02-02T10:05:11.242021888Z 0.03499999999985448
2018-02-02T10:10:10.689827072Z 0.033999999999650754
2018-02-02T10:15:12.143326976Z 0.02900000000045111
2018-02-02T10:20:10.753357056Z 0.0319999999992433
2018-02-02T10:25:11.18448512Z 0.03499999999985448
2018-02-02T10:30:12.922032896Z 0.033999999999650754
2018-02-02T10:35:10.618788096Z 0.030000000000654836
2018-02-02T10:40:11.820355072Z 0.03299999999944703
2018-02-02T10:45:11.634203904Z 0.028000000000247383
2018-02-02T10:50:11.10436096Z 0.02200000000084401
2018-02-02T10:55:10.753853952Z 0.02299999999922875
Where I struggle is getting this to work in a continuous query. Here is the command I used to setup the continuous query:
CREATE CONTINUOUS QUERY cq_Haushaltstromzaehler_cnt ON myhomedb
BEGIN
SELECT difference(sum("Haushaltstromzaehler - cnt")) AS "delta" INTO "Haushaltstromzaehler_delta" FROM "myhome_measurements" GROUP BY time(1h)
END
Looking in the InfluxDB log file I see that no data is written in the new 'delta' measurement from the continuous query execution:
...finished continuous query cq_Haushaltstromzaehler_cnt, 0 points(s) written...
After much troubleshooting and experimenting I now understand why no data is generated. Setting up a continuous query requires to use the GROUP BY time() statement. This in turn requires to use an aggregate function within the differences() function. The problem now is that the aggregate function returns only one value for the time period specified by GROUP BY time(). Obviously, the differences() function cannot calculate a difference from just one value. Essentially, continuous query executes a command like this:
> SELECT difference(sum("Haushaltstromzaehler - cnt")) FROM "myhome_measurements" WHERE time >= '2018-02-02T10:00:00Z' AND time < '2018-02-02T11:00:00Z' GROUP BY time(1h)
>
I'm now somewhat clueless as to how to make this work and appreciate any advice you might have.
Does it help using the last aggregate function? Not tested this as a cq yet.
Select difference(last(T1_Consumed)) AS T1_Delta, difference(last(T2_Consumed)) AS T2_Delta
from P1Data
where time >= 1551648871000000000 group by time(1h)
DIFFERENCE() would calculate delta from the "aggregated" value taken from previous group, not within current group.
So fill free to use selector function there - since your counters seemed to be cumulative, LAST() should be working well.
select SUM(value)
from /measurment1|measurment2/
where time > now() - 60m and host = 'hostname' limit 2;
Name: measurment1
time sum
---- ---
1505749307008583382 4680247
name: measurment2
time sum
---- ---
1505749307008583382 3004489
But is it possible to get value of SUM(measurment1+measurment2) , so that I see only o/p .
Not possible in influx query language. It does not support functions across measurements.
If this is something you require, you may be interested in layering another API on top of influx that do this, like Graphite via Influxgraph.
For the above, something like this.
/etc/graphite-api.yaml:
finders:
- influxgraph.InfluxDBFinder
influxdb:
db: <your database>
templates:
# Produces metric paths like 'measurement1.hostname.value'
- measurement.host.field*
Start the graphite-api/influxgraph webapp.
A query /render?from=-60min&target=sum(*.hostname.value) then produces the sum of value on tag host='hostname' for all measurements.
{measurement1,measurement2}.hostname.value can be used instead to limit it to specific measurements.
NB - Performance wise (of influx), best to have multiple values in the same measurement rather than same value field name in multiple measurements.
I'm trying to leverage my moderate SQL-knowledge for InfluxQL, but I'm missing something(s) about the nature of timeseries db.
Use case
I write a measurements from our issue tracker, when an issue is updated:
issue_updated,project=facebook,ticket=fb1,assignee=coolman status="todo"
Problem
Given this returns rows of issues statuses:
SELECT status
FROM "issue_updated"
If this was SQL (fiddle) I would use COUNT(and then add the WHERE time > NOW() - 1Y GROUP BY time(5m)). However the following gives me Mixing aggregate and non-aggregate queries is not supported
SELECT status, count(status) as 'Count'
FROM "issue_updated"
Can someone give some guidance here? ta
Sounds like what you're looking for is the ability to group by a field value which isn't currently supported.
From what I can tell, if you modify your schema a bit, it should be possible to do what you're looking. Instead of
issue_updated,project=facebook,ticket=fb1,assignee=coolman status="todo"
Do
issue_updated,project=facebook,ticket=fb1,assignee=coolman,status=todo value=1
then
SELECT count(value) FROM "issue_updated" WHERE time > now() - 52w GROUP BY status
name: issue_updated
tags: status=other
time count
---- -----
1449523659065350722 1
name: issue_updated
tags: status=todo
time count
---- -----
1449523659065350722 2
should work.