franckstifler
Use alias field in select ecto
Hi. I have a query that looks like this:
from p in Payment, group_by: fragment("extract(hour from ?) as hour", p.inserted_at),
select: {fragment("max(?)", p.amount)}
How can I get my group_by field (hour) in the select using this query?
Most Liked
1player
Don’t quote me on this, but I don’t think it is possible.
I have a vague recollection of trying to order some results depending on the result of an expression in the select, and the only way to make it work was to repeat the expression verbatim in the order_by clause.
Unless I’m wrong, you’ll have to do
from p in Payment, group_by: fragment("extract(hour from ?) as hour", p.inserted_at),
select: {
fragment(max("?", p.amount)),
fragment("extract(hour from ?) as hour", p.inserted_at)
}
and hope PostgreSQL is smart enough to compute that expression only once. Alternatively you can write a raw query.
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Enabling companies to succeed by building software people love.
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.
Practical resources that improve the lives of professional developers.
Develop your skills with books, videos, and courses.
Enabling companies to succeed by building software people love.
Courses that'll move you from confusion to "Aha, now I get it!"