so, you essentially want to do something like (.toDate ?my-datetime) just before returning the results?

you can't use Clojure's Java interop like that directly within a query, but you can wrap the call in a Clojure function that can be used as a custom predicate

like

(defn datetime->date [dt]
  (.toDate dt))

(crux/q db '{:find [d]
             :where [[:my-e :date my-date]
                     [(my.ns/datetime->date my-date) d]]}

thanks @U899JBRPF I will test this. My idea is that I am using aggregation and want to aggregate by date not datetime

worked just fine. Great! Thanks again @U899JBRPF

I noticed the need to specify the namespace, so do you have more docs on custom predicates?

No additional docs at the moment...but that's pretty much all there is to it. You can also destructure the output like :in

We have various examples in the tests

cool, thanks for pointing these out

if you're not using the date within the query, it might be more straightforward to operate on the resultset instead - (->> (crux/q ...) (map first) (map ->date))

or (map #(update % 0 ->date)), there's a whole load of different ways 🙂