Clojurians Log v2
xtdb 2025-05-17
Question about the inline XTQL stuff in Beta 8 @jarohen :
FROM (XTDB $$ (-> (from :my-table [x]) (where (<= x 100))) $$) AS my_tableFROM XTDB $$ (-> (from :my-table [x]) (where (<= x 100))) $$ AS my_tableI'm implementing this in HoneySQL, which is why I'm asking...
I've implemented like this for now:
user=> (sql/format [:xtql '(-> (from :my-table [x]) (where (<= x 100)))])
["XTQL $$ (-> (from :my-table [x]) (where (<= x 100))) $$"]
user=> (sql/format {:from [[[:xtql '(-> (from :my-table [x]) (where (<= x 100)))] :my_table]]})
["FROM (XTQL $$ (-> (from :my-table [x]) (where (<= x 100))) $$) AS my_table"]
you don't waste your time 😄🙏
yes, parens required when it's being used within a wider SQL query, optional at top-level
this is mainly just following the syntax for SQL subqueries, I can see whether we can unambiguously remove them for XTQL specifically if that would make things easier
No, it's fine, I just wanted to figure out the implementation. Seems I guessed right 🙂
also you may run into https://github.com/xtdb/xtdb/pull/4443 when you start testing with params - it's ugly, I'm ashamed of it, and any better suggestions welcome 😬
Nasty indeed. I'll have to give that some thought.
I created a HoneySQL issue to think about it...
I guess HoneySQL could look at the XTQL form and see (fn [a b c] ..) and add 3 ? parameters...
fwiw in the Clojure API we've done a relatively simple parse of the XTQL and ... yep, that
One thing to be aware of here is how '#(...) behaves for that pr-str call:
{:from [[[:xtql '#(-> (from :my-table [x]) (where (<= x %))) :my_table]]]}
;;=>
["FROM (XTQL $$ (fn* [p1__32122#] (-> (from :my-table [x]) (where (<= x p1__32122#)))) $$) AS my_table"]And I suspect you don't support fn* there? 🙂
How are the actual parameters passed in this case?
As in, how would HoneySQL know to lift values out and provide ? placeholders?
yep, we deliberately do support fn* 🙂
so we check first is fn or fn*, then count second
OK... so maybe [:xtsql '(fn [v] (-> (from :my_table [x]) (where (<= x v))) 42] as the HoneySQL format?
To produce ["XTQL ($$ .. $$, ?)" 42]
that seems good, yeah - :xtql I guess?
Yeah... I have a hard time typing that correctly.
ah, there's some good real user feedback 😄
Even in the tests I was just writing for HoneySQL, I repeatedly got it wrong and the tests failed 😞
Per https://github.com/xtdb/xtdb/pull/4443, parameters can be
provided to :xtql after the XTQL form, which must either use (fn [..] ..)
or the #(..) shorthand syntax to parameterize the query:
clojure
user=> (sql/format {:from [[[:xtql '(fn [v] (-> (from :my-table [x]) (where (<= x v)))) 42] :my_table]]})
["FROM (XTQL ($$ (fn [v] (-> (from :my-table [x]) (where (<= x v)))) $$, ?)) AS my_table" 42][:xtql '#(-> (from :my-table [x]) (where (<= x %)) 42].> which must either use the fn or #() syntax > this is the only way to do params in XTQL after beta8. tbh I'm hoping that it's only ever you and us that need to worry about the extra ?s 🙂 - anyone going through the xtdb-api should have it handled transparently on their behalf
FYI