Adding schema to database (not connection)

gistfile1.clj

(use '[datomic.api :only [q db] :as d])

(def uri "datomic:mem://schema-test")

(d/delete-database uri)
(d/create-database uri)

(def conn (d/connect uri))

(def schema-tx
  [{:db/id (d/tempid :db.part/db)
    :db/ident :person/name
    :db/valueType :db.type/string
    :db/cardinality :db.cardinality/one
    :db.install/_attribute :db.part/db}])

@(d/transact conn schema-tx)

(defn latest-transaction-time []
  (ffirst
   (reverse (sort (q '[:find ?when :where [_ :db/txInstant ?when]]
                     (db conn))))))

(def before (latest-transaction-time))

(def migrate-schema-tx 
  [{:db/id (d/tempid :db.part/db)
    :db/ident :person/debt
    :db/valueType :db.type/long
    :db/cardinality :db.cardinality/one
    :db.install/_attribute :db.part/db}])

(let [db (d/as-of (db conn) before)]
  (d/with db migrate-schema-tx))