Logql - how to cast litertal to vector

Hi,

what’s the equivalent of promql’s vector(0) in loki?

I have the following query
sum by (app) (sum_over_time{file="/logs/myapp.log"} |= “error” [1m]})

and I want to add a grafana alert on it whenever the resulting number is greater than 0

now I don’t want to handle the no data scenario and in prometheus I would do something along the lines of:
(query) or vector(0) and this would fill all the missing values with 0.

Is there any way to do the same in loki?

I’m currently running loki 2.3