Thanks

Is it possible to pass a pull pattern that contains some :default settings to query? If so - what’s the correct format? I get an error:

(d/q '[ :find (pull ?j query)
        :in $ ?bin query
        :where
        [?j :job/bin ?bin]]
  db
  "1047470"
  '[ (:job/fully-paid :default false) ])

datomic.impl.Exceptions$IllegalArgumentExceptionInfo: :db.error/invalid-attr-spec Cannot interpret as an attribute spec: (:job/fully-paid :default false) of class: class clojure.lang.PersistentList

@donmullen you might want to look at https://docs.datomic.com/cloud/query/query-data-reference.html#get-else and https://docs.datomic.com/cloud/query/query-pull.html#default-option

@marshall I’ve used get-else successfully in queries - but not :default in a pull pattern. Not sure what I’m missing. My example above seems to follow pattern in the docs :

[:artist/name (:artist/endYear :default "N/A")] 

;; default option
(d/pull db '[:artist/name (:artist/endYear :default 0)] mccartney)

ahh; don’t think you can pass the pull expr as a parameter

if you’re using it in the find expression

oh, yes you can

hrm. one second 🙂

@marshall I also got that error using d/pull as well which I was thinking would surely work - hmmm…

what version of datomic/

?

or is this in cloud?

datomic-pro-0.9.5651

ah

that feature was released in 5656

http://blog.datomic.com/2017/12/datomic-pull-as.html

there is an older syntax for limit exprs, but the one you’re using there ^ is the newer one based on attr-with-options

https://docs.datomic.com/on-prem/pull.html#sec-2-2

OK - thanks @marshall

(d/q '[:find [(pull ?e pattern) ...]
       :in $ ?artist pattern
       :where [?e :release/artists ?artist]]
     db
     led-zeppelin
     '[(:release/name :as "Release")])

^ that gives:

[{"Release" "Houses of the Holy"} {"Release" "Immigrant Song / Hey Hey What Can I Do"} {"Release" "Immigrant Song / Hey Hey What Can I Do"} {"Release" "Heartbreaker / Bring It On Home"} {"Release" "Led Zeppelin III"} {"Release" "Whole Lotta Love / Living Loving Maid"} {"Release" "Led Zeppelin III"} {"Release" "Led Zeppelin III"} {"Release" "Led Zeppelin"} {"Release" "Led Zeppelin IV"} {"Release" "Led Zeppelin"} {"Release" "Led Zeppelin IV"} {"Release" "Led Zeppelin"} {"Release" "Led Zeppelin II"} {"Release" "Led Zeppelin II"} {"Release" "Led Zeppelin II"} {"Release" "Led Zeppelin II"}]

based on this example: https://github.com/Datomic/day-of-datomic/blob/master/tutorial/pull.clj#L113

limit and default should work the same way