gistfile1.clj

(def uri "datomic:mem://testdb")

(d/create-database uri)
(def conn (d/connect uri))
  
;; The schema
(def s [{:db/id #db/id[:db.part/db]
         :db/ident :testdb/test
         :db/valueType :db.type/boolean
         :db/cardinality :db.cardinality/one
         :db.install/_attribute :db.part/db}])
  
(d/transact conn s)

;; Add two facts to the db
(d/transact conn [[:db/add #db/id[:db.part/db] :testdb/test true]
                  [:db/add #db/id[:db.part/db] :testdb/test false]])

(defn query [b]
  (q '[:find ?e
       :in $ ?b
       :where
       [?e :testdb/test ?b]]
     (db conn) b))

(query true) ;; OK, #<HashSet [[63]]>
(query false) ;; Throws an exception:
                ;; Unable to find data source: $38171