critical feature - you can now unset fields.

src/clj/auto_ap/datomic.clj

@@ -30,7 +30,6 @@
       (update-in [:args] into (get-in query-part-2 [:args]))))
 
 (defn remove-nils [m]
-
   (let [result (reduce-kv
          (fn [m k v]
            (if (not (nil? v))
@@ -43,6 +42,25 @@
       result
       nil)))
 
+(defn replace-nils-with-retract [updated original]
+  (let [result (reduce-kv
+                (fn [[m & retractions] k v]
+                  (cond (and (nil? v)
+                             (not (nil? (get original k))))
+                        (into [m] (conj retractions [:db/retract (:db/id original) k (or (:db/id (get original k))
+                                                                                         (get original k))]))
+
+                        (nil? v)
+                        (into [m] retractions)
+
+                        :else
+                        (into [(assoc m k v)] retractions)))
+                [{}]
+                updated)]
+    (if (seq result)
+      result
+      nil)))
+
 
 (def vendor-schema
   [{:db/ident :vendor/original-id