I'm trying to use a variable at the start of one of my PromQL queries so I can return data based on the variable. Not sure if this is possible or not.
$variable_totalaccuracy_total
Expected to return the totalaccuracy for the variable but get back
error:"parse error at char 1: unexpected character: '$'"
Use braces around the variable name:
${variable}_totalaccuracy_total
Related
I'm trying to use Query Variables in Grafana, the panel query source is PostgreSQL for QuestDB.
I have added the variable without any issue, but I'm unable to use the variable in Panel query since the variable values contains the spaces (SENSOR01 ON_OFF), also I'm unable to figure-out how to add single quote escape.
Following are the scenarios I tried:
Scenario1: this indicates due to space in the Variable value, on_off considered as separate word
where sensor_name = $sensor
db query error: pq: unexpected token: on_off
.
.
Scenario2: tried to add single quotes explicitly for the variable value, but there is generic error from source DB (QuestDB)
where sensor_name = concat('''', $sensor, '''')
db query error: pq: dangling expression
When tried Scenario2 approach directly in query of Variable, getting the same error
..
Scenario3: Hard-coded the variable value with space and with single quotes, but this giving me error with first part of the variable, looks like the hard-coded single quotes not passed here!
Error (Scenario3):
Is there any way/workaround to tackle this issue?
Could you just add the quotes directly in the query?
where sensor_name = '$sensor'
I have a similar grafana panel querying a questDB database using a variable and it works for me. This is my query:
select device_type, avg(duration_ms) as avg_duration_ms, avg(speed) as avg_speed, avg(measure1) as avg_m1, avg(measure2) as avg_m2 from ilp_test
WHERE
$__timeFilter(timestamp) and device_type = '$deviceType'
A rather hacky workaround would be to do:
where sensor_name = concat(cast(cast('&' as int) + 1 as char), $sensor, cast(cast('&' as int) + 1 as char))
This should work, but I'm pretty sure there is a better solution. Let me find it and get back to you.
Update. We may support Postgres syntax (which is '' escaping for a single quote char) in one of upcoming versions. For now, you'd have to use the above workaround.
I am setting a Variable in Grafana.
I want to create a Query, that only returns a subset of the labels with value app the ones I want to return are those ending in dev
My Query so far, returns all of the labels with value app successfully. However, I have been unable to successfully filter the values so that only a-dev b-dev and c-dev are returned.
How do I successfully apply regex (or alternative) to this query so that I can see the desired values?
Any help on this would be greatly appreciated!
I eventually figured out what I needed to do. Originally I was trying to use | to run regex on the results from label_values.
However, this format worked:
label_values({app=~".*-dev$"}, app)
and returned only a-dev b-dev c-dev as expected.
I am trying to take the value of a drop down I created in grafana, utilizing a query variable.
I am using SimpleJSON for my database.
I have tried this pattern where:
var is my variable that makes up the drop down menu
func is my function call for the database query that creates the graph
So then I wrote:
f.g.func[$var]
I get a Internal Server Error yet when I call func in kdb+ with the values directly, it works fine. So I think I'm passing in var incorrectly.
For grafana/kdb+ adaptor, the syntax is f.g.func["$var"]-- my above attempt lacks the quotes necessary
The following lines of Q code all throw an error, because when the statement "local" is parsed, the local variable is not in the correct scope.
{local:1; value "local"}[]
{[local]; value "local"}[1]
{local:1; eval parse "local"}[]
{[local]; eval parse "local"}[1]
Is there a way to reach the local variable from inside the parsed string?
Note: This is a simplification of the actual problem I'm grappling with, which is to write a function that executes a query, accepting a list of columns which it should return. I imagine the finished product looking something like this:
getData:{[requiredColumns, condition]
value "select ",(", " sv string[requiredColumns])," from myTable where someCol=condition"
}
The condition parameter in this query is the one that isn’t recognised and I do realise I could append it’s value rather than reference it inside a string, but the real query uses lots of local variables including tables etc, so it’s not as easy as just pulling all the variables out of the string before calling value on it.
I'm new to KDB and Q, so if anyone has a better way to achieve the same effect I'm happy to be schooled on the proper way to achieve this outcome in Q. Would still be interested to know in the variable access thing is possible though.
In the first example, you are right that local is not within the correct scope, as value is looking for the global variable local.
One way to get around this is to use a namespace, which will define the variable globally, but can only be accessed by calling that namespace. In the modified example below I have defined local in the .ns namespace
{.ns.local:1; value ".ns.local"}[]
For the problem you are facing with selecting, if requiredColumns is a symbol list of columns you can just use the take operator # to select them.
getData:{[requiredColumns] requiredColumns#myTable}
For more advanced queries using variables you may have to use functional select form, explained here. This will allow you to include variables in the where and by clause of the select statement
The same example in functional form would be (no by clause, only select and where):
getData:{[requiredColumns;condition] requiredColumns:(), requiredColumns;
?[myTable;enlist (=;`someCol;condition);0b;requiredColumns!requiredColumns]}
The first line ensures that requiredColumns is a list even if the user enters a single column name
value will look for a variable in the global scope that's why you are getting an error. You can directly use local variables like you are doing that in your function.
Your function is mostly correct, just need a slight correction to append condition(I have mentioned that below). However, a better approach would be to use functional select in this case.
Using functional select:
q) t:([]id:`a`b; val:3 4)
q) gd: {?[`t;enlist (=;`val;y);0b;((),x)!(),x]}
q) gd[`id;3] / for single column
Output:
id
-
1
q) gd[`id`val;3] / for multiple columns
In case your condition column is of type symbol, then enlist your condition value like:
q) gd: {?[`t;enlist (=;`id;y);0b;((),x)!(),x]}
q) gd[`id;enlist `a]
You can use parse to get a functional form of qsql queries:
q) parse " select id,val from t where id=`a"
?
`t
,,(=;`id;,`a)
0b
`id`val!`id`val
Using String concat(your function):
q)getData:{[requiredColumns;condition] value "select ",(", " sv string[requiredColumns])," from t where id=", .Q.s1 condition}
q) getData[enlist `id;`a] / for single column
q) getData[`id`val;`a] / for multi columns
I have several metrics with the label "service". I want to get a list of all the "service" levels that begin with "abc" and end with "xyz". These will be the values of a grafana template variable.
This is that I have tried:
label_values(service) =~ "abc.*xyz"
However this produces a error Template variables could not be initialized: parse error at char 13: could not parse remaining input "(service_name) "...
Any ideas on how to filter the label values?
This should work (replacing up with the metric you mention):
label_values(up{service=~"abc.*xyz"}, service)
Or, in case you actually need to look across multiple metrics (assuming that for some reason some metrics have some service label values and other metrics have other values):
label_values({__name__=~"metric1|metric2|metric3", service=~"abc.*xyz"}, service)