ring app

core.clj

(ns simple-ring.core
  (:require [datomic.api :as d]))

(def uri "datomic:dev://localhost:4334/5745c8fc-6d57-4184-972a-eef798243572")

(def schema-tx
  [{:db/id #db/id[:db.part/db]
    :db/ident :hello/color
    :db/valueType :db.type/string
    :db/cardinality :db.cardinality/one
    :db/fulltext true
    :db/doc "Today's color"
    :db.install/_attribute :db.part/db}])

(def data-tx
  [{:db/id #db/id[:db.part/user -1], :hello/color "True Mint"}
   {:db/id #db/id[:db.part/user -2], :hello/color "Yellowish White"}
   {:db/id #db/id[:db.part/user -3], :hello/color "Orange Red"}
   {:db/id #db/id[:db.part/user -4], :hello/color "Olive Green"}])

(defn init-db []
  (let [_ (prn ::init-db uri schema-tx data-tx)
        created? (d/create-database uri)
        _ (prn ::init-db "created?" created?)
        conn (d/connect uri)
        _ (prn ::init-db conn)]
    @(d/transact conn schema-tx)
    @(d/transact conn data-tx)
    conn))

(defn simple-query
  [conn]
  (let [conn (d/connect uri)]
    (d/q '[:find ?c :where [?e :hello/color ?c]] (d/db conn))))

(defn handler [request]
  (let [conn (init-db)]
    {:status 200
     :headers {"Content-Type" "text/plain"}
     :body (str "Hello Ring! " (simple-query conn))}))