zediogoviana
Ecto Fragment interpolating var in group_by and select
I am trying to the following:
query =
from s in State,
group_by:
fragment("date_part(?, ?)", ^group, s.timestamp_start),
select:
{fragment("date_part(?, ?)", ^group, s.timestamp_start), count(s.id)}
Repo.all(query)
Where group might be one of [‘minute’, ‘hour’, ‘day’].
However, I get the following error:
ERROR 42803 (grouping_error) column "s0.timestamp_start" must appear in the GROUP BY clause or be used in an aggregate function
But if I add s.timestamp_start to group_by clause, I don’t get the expected result, since dates are grouped by timestamp_start and not by the part defined.
How can I do this without having to specify a query to each group possibility (passing the literal value inside fragment ) ?
Marked As Solved
KristerV
bump! since I desperately need the answer to the same question :s
edit: after hours found a solution:
from(m in Message,
where:
m.user == ^user
group_by: [
fragment("timestamp")
],
select: {
fragment("date_trunc(?, ?) as timestamp", ^timeseries, m.inserted_at),
fragment("array_agg(?)", m.body)
}
)
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
We build reliable cloud platforms for business-critical systems.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Develop your skills with books, videos, and courses.
Enabling companies to succeed by building software people love.
The deployment platform built for Elixir: PaaS ease, VPS control.
Courses that'll move you from confusion to "Aha, now I get it!"