fix: schema not fully support

Author: tiensonqin

src/datascript/db.cljc

@@ -1285,14 +1285,16 @@
         (let [err-msg (str "Schema with attribute " v-ident " does not exist")
               err-map {:error :retract/schema :attribute v-ident}]
           (throw (ex-info err-msg err-map)))
-        (update-in db [:schema] #(dissoc % v-ident)))
-      (let [e-ident (:v (first (-seek-datoms db :eavt e :db/ident nil nil)))]
-          (if (schema e-ident)
-            (update-in db [:schema e-ident] #(dissoc % a-ident))
-            (let [err-msg (str "Schema with db/ident " e-ident " does not exist")
-                  err-map {:error :retract/schema :entity-id e :attribute a :value e}]
-              (throw #?(:clj (ex-info err-msg err-map)
-                        :cljs (ex-info err-msg err-map)))))))))
+        (-> db
+            (assoc-in [:schema e] (dissoc (schema v-ident) a-ident))
+            (update-in [:schema] #(dissoc % v-ident))))
+      (if-let [schema-entry (schema e)]
+        (if (schema schema-entry)
+          (update-in db [:schema schema-entry] #(dissoc % a-ident))
+          (update-in db [:schema e] #(dissoc % a-ident v-ident)))
+        (let [err-msg (str "Schema with entity id " e " does not exist")
+              err-map {:error :retract/schema :entity-id e :attribute a :value e}]
+          (throw (ex-info err-msg err-map)))))))
 
 (defn get-schema [db]
   (or (:schema db) {}))
@@ -1305,9 +1307,14 @@
         a-ident a
         v-ident v]
     (if (= a-ident :db/ident)
-      (assoc-in db [:schema v-ident a-ident] v-ident)
-      (let [e-ident (:v (first (-seek-datoms db :eavt e :db/ident nil nil)))]
-        (assoc-in db [:schema e-ident a-ident] v-ident)))))
+      (-> db
+          (assoc-in [:schema v-ident] (merge (or (schema e) {}) (hash-map a-ident v-ident)))
+          (assoc-in [:schema e] v-ident))
+      (if-let [schema-entry (schema e)]
+        (if (schema schema-entry)
+          (assoc-in db [:schema schema-entry a-ident] v-ident)
+          (assoc-in db [:schema e a-ident] v-ident))
+        (assoc-in db [:schema e] (hash-map a-ident v-ident))))))
 
 (defn update-rschema [db]
   (assoc db :rschema (rschema (merge implicit-schema (get-schema db)))))