I have a db of hydrological data.
I wrote a cell in the influxdata panel to find the first occurrence where the measurement is above 17°.
But now I don't want to display the value but the timestamp in the cell when the first occurence was:
from(bucket: "hydroAPI")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "hydro")
|> filter(fn: (r) => r["_field"] == "temperature")
|> filter(fn: (r) => r["loc"] == "XXXX")
|> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
|> filter(fn: (r) => r._value > 17 )
|> first()
|> yield(name: "mean")
This code is working, but it shows just the value. I want to see the time. Is this possible?
The Single Stat visualization will always display what's in the _value column, so you need to replace that with your time.
Try adding this just before your yield():
|> drop(columns: ["_value"])
|> rename(columns: {_time: "_value"})
|> toString()
The first line drops the _value column so that you can rename the _time column in the second line. Since you probably don't want the timestamp in nanoseconds, the toString() on the third line will convert it into a human-readable form.
Related
I’m tryingto sum values in InfluxDB but I’m struggling a bit.
So, I have a _measurement "plug" with a field "value".
I have different records within the same bucket with a different ID tag.
I can get the evolution of 1 plug with this query:
from(bucket: "test-bucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "plug")
|> filter(fn: (r) => r["_field"] == "value")
|> filter(fn: (r) => r["id"] == "tag1")
|> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
|> yield(name: "mean")
What I would like is the exact same graph with the sum of all r["id"].
So, if there is 34 for tag ID "tag1", 11.2 for "tag2" and 0 for "tag3", I would like a graph with 45.2 for that given time.
I’ve tried to use «group()» method, but I get a strange value, more like an average than a sum.
I’ve also tried to use «sum» method, but then, I feel like Influx is summing all the values across the whole timeline. That’s not what I want.
I just like to have a graph with with the sum of «value» field of all "tag" at a given time.
Thanks a lot for you help.
Right now you have a table per tag value. You can use pivot function to merge into a single table, where all the different _value columns are now named after their corresponding tag value:
from(bucket: "test-bucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r._measurement == "plug")
|> filter(fn: (r) => r._field == "value")
|> pivot(rowKey: ["_time"], columnKey: ["id"], valueColumn: "_value")
If you know the tag values in advance, the next step is easy:
|> map(fn: (r) => ({ _time: r._time, _value: r["tag1"] + r["tag2"] + r["tag3]}))
If you don't, it gets a bit more complicated. What I would try next in this case is to write a function that combines experimental.unpivot() (note: available since InfluxDB 2.4) with sum(). The trick here is to call this method within map(), so it will operate on a single row (ie, single timestamp) at a time:
sumColumns = (r) => r
|>experimental.unpivot()
|>group
|>sum()
|>findRecord(fn: (key) => true, idx: 0)
from(bucket: "test-bucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r._measurement == "plug")
|> filter(fn: (r) => r._field == "value")
|> pivot(rowKey: ["_time"], columnKey: ["id"], valueColumn: "_value")
|> map(fn: sumColumns)
Note that I have not tested this. It is just to give you an idea.
we are using the influxDB for statistics and dashboards. We love it! Blazing fast and easy to integrate. However we are stuck when we launch new features.
We have the following FLUX query. A massive database with all "model_events" based on the businessUUID. However if the business doesn't have a car.created it returns no results instead of a range with 0's. If it has one car.created even without the range it will return a 0 range. Is there a possibility to always get the range even if the _measurement doesn't have a value?
from(bucket: "_events")
|> range(start: 2022-09-01, stop: 2022-09-11)
|> filter(fn: (r) => r["_measurement"] == "car.created")
|> filter(fn: (r) => r["business_uuid"] == "055ade92-ecd9-47b1-bf85-c1381d0afd22")
|> aggregateWindow(every: 1d, fn: count, createEmpty: true)
|> yield(name: "amount")
BTW.... a bit new to InfluxDB...
Maybe you could create a dummy table and union() it like:
import "experimental/array"
rows = [{_time: now(), _field: "someField", _value: 0}]
dummy = array.from(rows: rows)
data = from(bucket: "_events")
|> range(start: 2022-09-01, stop: 2022-09-11)
|> filter(fn: (r) => r["_measurement"] == "car.created")
|> filter(fn: (r) => r["business_uuid"] == "055ade92-ecd9-47b1-bf85-c1381d0afd22")
|> aggregateWindow(every: 1d, fn: count, createEmpty: true)
|> yield(name: "amount")
union(tables: [dummy, data])
Trying to write my fist TICKscript to work out when two sensor values cross: if the outside temperature has changed from lower to higher than the inside temperature then I need to close the windows (and conversely).
Using the query builder in InfluxDB I'm getting this for the meadian of the temperature values inside the house over the last 15 minutes:
from(bucket: "zigbee")
|> range(start: -15m, stop: now())
|> filter(fn: (r) => r["room"] == "Kitchen" or r["room"] == "DiningRoom" or r["room"] == "Bed3" or r["room"] == "Bed1")
|> filter(fn: (r) => r["_field"] == "temperature")
|> group(columns: ["_measurement"])
|> aggregateWindow(every: 15m, fn: mean, createEmpty: false)
|> yield(name:"inside")
The syntax |> appears to undocumented -- can you provide a reference?
Replacing |> with | breaks it.
It seems that group and aggregateWindow do not commute?
Presumably because aggregateWindow is forced to choose a single representative _time value for each window?
I think the plan is to
assign this to a stream,
copy and edit to creata a second stream shifted by 15 minutes,
create a second pair of streams for the outside temperature.
join all four streams and caluclate a value indicating whether the inside and outside temperatures have crossed over.
Unless you have a better idea?
(Right now it's looking easier to import the data into SQL.)
Check InfluxDB Flux language documentation for |>:
InfluxDB Pipe-forward operator
According to your flux syntax query:
from(bucket: "zigbee")
|> range(start: -15m, stop: now())
|> filter(fn: (r) => r["room"] == "Kitchen" or r["room"] == "DiningRoom" or r["room"] == "Bed3" or r["room"] == "Bed1")
|> filter(fn: (r) => r["_field"] == "temperature")
|> group(columns: ["_measurement"])
|> aggregateWindow(every: 15m, fn: mean, createEmpty: false)
|> yield(name:"inside")
You are taking data from bucket "zigbee"
Data from source are passed to range filter function with pipe-forward |> operator
Results from range filter data are passed to next filter function with another pipe-forward operator
Etc.
So all data flows as a result from one function to another.
You can group by but in your case columns are "room" key values if I understand your intentions correctly, so try:
|> group(columns: ["room"])
There is a difference between key values and measurement names - you should check InfluxDB documentation for understatnding data structure.
Flux data model documentation
I'ts not TICKscript, it's something do to with InfluxDB that might be called flux.
mean = from(bucket: "zigbee")
|> range(start: -5d, stop: now())
|> filter(fn: (r) => r["room"] == "Outside")
|> filter(fn: (r) => r["_measurement"] == "temperature")
|> aggregateWindow(every: 30m, fn: mean, createEmpty: false)
shift = mean
|> timeShift(duration: -3h)
j = join(tables: {mean: mean, shift: shift}, on: ["_time"])
|> map(fn: (r) => ({ r with diff: float(v: r._value_mean) - float( v: r._value_shift) }))
// yield contains 1 table with the required columns, but the UI doesn't understand it.
// The UI requires 1 table for each series.
j |> map(fn: (r) => ({_time: r._time, _value: r._value_mean})) |> yield(name: "mean")
j |> map(fn: (r) => ({_time: r._time, _value: r._value_shift})) |> yield(name: "shift")
j |> map(fn: (r) => ({_time: r._time, _value: r.diff})) |> yield(name: "diff")
The |> in TickScript "Declares a chaining method call which creates an instance of a new node and chains it to the node above it." as said in the official documentation
I'm migrating my InfluxDB1.8 version to InfluxDB2.0
I'm using a influxDB2.0 database and use grafana to display results.
What I insert as data are the results of my P1 meter, altough the results are total values, I would like to calculate and display the daily results.
What is being inserting is the current (gas usage) value. By calculating the difference of the begin and end of the day, I have my daily usage result.
I did find out a way to do this for 1 day. With the Spread function. But I don't get it working for a longer timeframe then 1 day.
But now to display this on a daily usage on a longer timeframe. I didn't find the right option to get this working
Week results
Anyone an idea?
Query for 1 day:
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "Gas-usage")
|> filter(fn: (r) => r["_field"] == "value")
|> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
|> spread(column: "_value")```
I did some checks on the 1.8 one and what works there is:
SELECT spread("value")
FROM "Gas-usage"
WHERE $timeFilter
GROUP BY time(1d) fill(null) tz('Europe/Berlin')
what is the equivalant of this query in influxdb 2.0 ?
Try change your aggregate window, like this:
|> aggregateWindow(every: 1d, fn: mean)
use the spread function inside your aggreagateWindow function.
should be like this:
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "Gas-usage")
|> filter(fn: (r) => r["_field"] == "value")
|> aggregateWindow(every: 1d, fn: spread, createEmpty: false)
from(bucket: "${bucket}")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "system")
|> filter(fn: (r) => r.host == "${host}")
|> filter(fn: (r) => r["_field"] == "uptime")
|> aggregateWindow(every: 1d, fn: spread, createEmpty: false)
result of my grafana
I am trying to create two new columns with the first and last values using the last() and first() functions. However the function isn’t working when I try to map the new columns. Here is the sample code below. Is this possible using Flux?
from(bucket: "bucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "price_info")
|> filter(fn: (r) => r["_field"] == "price")
|> map(fn: (r) => ({r with
open: last(float(v: r._value)),
close: first(float(v: r._value)),
})
I am not answering directly to the question, however it might help.
I wanted to perform some calculation between first and last, here is my method, I have no idea if it is the right way to do.
The idea is to create 2 tables, one with only the first value and the other with only the last value, then to perform a union between both.
data = from(bucket: "bucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "plop")
l = data
|> last()
|> map(fn:(r) => ({ r with _time: time(v: "2011-01-01T01:01:01.0Z") }))
f = data
|> first()
|> map(fn:(r) => ({ r with _time: time(v: "2010-01-01T01:01:01.0Z") }))
union(tables: [f, l])
|> sort(columns: ["_time"])
|> difference()
For an unknown reason I have to set wrong date, just to be able to sort values and take into account than first is before last.
Just a quick thank you. I was struggeling with this as well. This is my code now:
First = from(bucket: "FirstBucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "mqtt_consumer")
|> filter(fn: (r) => r["topic"] == "Counters/Watermeter 1")
|> filter(fn: (r) => r["_field"] == "Counter")
|> first()
|> yield(name: "First")
Last = from(bucket: "FirstBucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "mqtt_consumer")
|> filter(fn: (r) => r["topic"] == "Counters/Watermeter 1")
|> filter(fn: (r) => r["_field"] == "Counter")
|> last()
|> yield(name: "Last")
union(tables: [First, Last])
|> difference()
Simple answer is to use join (You may also use old join, when using "new" join remember to import "join")
Example:
import "join"
balance_asset_gen = from(bucket: "telegraf")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "balance")
|> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
balance_asset_raw = from(bucket: "telegraf")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "balance_raw")
|> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
// In my example I merge two data sources but you may just use 1 data source
balances_merged = union(tables: [balance_asset_gen, balance_asset_raw])
|> group(columns:["_time"], mode:"by")
|> sum()
f = balances_merged |> first()
l = balances_merged |> last()
// Watch out, here we assume we work on single TABLE (we don't have groups/one group)
join.left(
left: f,
right: l,
on: (l, r) => l.my_tag == r.my_tag, // pick on what to merge e.g. l._measurement == r._measurement
as: (l, r) => ({
_time: r._time,
_start: l._time,
_stop: r._time,
_value: (r._value / l._value), // we can calculate new field
first_value: l._value,
last_value: r._value,
}),
)
|> yield()