gistfile1.clj

(require '[datomic.api :as d])
(d/create-database "datomic:mem://example")
(def conn (d/connect "datomic:mem://example"))

(d/transact conn
            [{:db/id #db/id [:db.part/db -1]
             :db/ident :foo
             :db/valueType :db.type/string
             :db/cardinality :db.cardinality/one
             :db.install/_attribute :db.part/db}
             {:db/id #db/id [:db.part/db -2]
              :db/ident :baz
              :db/valueType :db.type/long
              :db/cardinality :db.cardinality/one
              :db.install/_attribute :db.part/db}
             {:db/id #db/id [:db.part/db -3]
              :db/ident :bloop
              :db/valueType :db.type/long
              :db/cardinality :db.cardinality/many
              :db.install/_attribute :db.part/db}
             {:db/id #db/id [:db.part/db -4]
              :db/ident :quux
              :db/valueType :db.type/string
              :db/cardinality :db.cardinality/one
              :db.install/_attribute :db.part/db}
             ])

(d/transact conn
            [{:db/id #db/id [:db.part/user -1] :foo "bar" :baz 5 :bloop #{1 2 3}}
             {:db/id #db/id [:db.part/user -2] :foo "bar" :baz 6 :bloop #{2 3}}
             {:db/id #db/id [:db.part/user -3] :foo "foo" :baz 6 :bloop #{2 1}}
             {:db/id #db/id [:db.part/user -4] :quux "bar" :baz 5}])

(assert  (= 1
            (count
              (d/q '[:find ?e
                     :in $ % ?attr-vals
                     :where
                     (has-values ?e ?attr-vals)]
                   (d/db conn)
                   '[[(has-values _ ?attr-vals)
                      [(empty? ?attr-vals)]]
                     [(has-values ?e ?attr-vals)
                      [(conj ?t ?h) ?attr-vals]
                      [(vector ?qf ?qv) ?h]
                      [?e ?qf ?qv]
                      (has-values ?e ?t)]]
                   [[:bloop 1]
                    [:baz 5]])))
        "This should only have one result")