fix #372

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changes
 
+* 2.1.next in progress
+  * Fix #372 by merging `:select-distinct-on` differently.
+  * Update `build-clj` to v0.6.0.
+
 * 2.1.829 -- 2021-11-27
   * Fix #371 by treating the operand of `NOT` as a nested expression (so it is parenthesized unless it is a simple value).
   * Fix #370 by **always** parenthesizing the operand of `:nest`.

deps.edn

@@ -4,7 +4,7 @@
  :aliases
  {;; for help: clojure -A:deps -T:build help/doc
   :build {:deps {io.github.seancorfield/build-clj
-                 {:git/tag "v0.5.5" :git/sha "0527130"}}
+                 {:git/tag "v0.6.0" :git/sha "2451bea"}}
           :ns-default build}
 
   ;; versions to test against:

src/honey/sql/helpers.cljc

@@ -110,10 +110,20 @@
           (simplify-logic))
       current)))
 
+(defn- select-distinct-on-merge
+  "Since the first argument in a group is special, we
+  need to merge that, and then merge the other args."
+  [[c-on & current] [a-on & args]]
+  (-> (c/into (vec c-on) a-on)
+      (vector)
+      (c/into current)
+      (c/into args)))
+
 (def ^:private special-merges
   "Identify the conjunction merge clauses."
-  {:where  #'conjunction-merge
+  {:select-distinct-on #'select-distinct-on-merge
-   :having #'conjunction-merge})
+   :where              #'conjunction-merge
+   :having             #'conjunction-merge})
 
 (defn- helper-merge [data k args]
   (if-let [merge-fn (special-merges k)]
@@ -400,6 +410,12 @@
   [& args]
   (generic :select-distinct-on args))
 
+(comment
+  (= (select-distinct-on [:a :b] :c [:d :dd])
+     (-> (select-distinct-on [:a] :c)
+         (select-distinct-on [:b] [:d :dd])))
+  )
+
 (defn select-top
   "Accepts a TOP expression, followed by any number of
   column names, or column/alias pairs, or SQL expressions