datascript entity export

gistfile1.clj

;;Export datoms, replacing eids w/ tempids so that the datoms can be imported into a second datascript/datomic db.

(let [db (d/db conn)

      eids (->> (d/q '{:find [?eid]
                       :in [$ %]
                       :where [(exportable ?eid)]}
                     db export-rules)
                (map first)
                set)

      temp-ids (zipmap eids (range -1000000 -1))

      ref-attrs (reduce-kv (fn [res attr schema]
                             (if (= :db.type/ref (:db/valueType schema))
                               (conj res attr)
                               res))
                           #{}
                           (:schema db))]

  (->> eids
       (mapcat (partial d/datoms db :eavt))
       (map (fn [{:keys [e a v]}]
              [(temp-ids e) a (if (ref-attrs a) (temp-ids v) v)]))))