Common tx in Datahike

common_tx.clj

(require '[datahike.api :as d])

(def schema [{:db/ident       :name
              :db/cardinality :db.cardinality/one
              :db/index       true
              :db/unique      :db.unique/identity
              :db/valueType   :db.type/string}
             {:db/ident       :sibling
              :db/cardinality :db.cardinality/many
              :db/valueType   :db.type/ref}
             {:db/ident       :age
              :db/cardinality :db.cardinality/one
              :db/valueType   :db.type/long}])

(def cfg {:store              {:backend :mem
                               :id "sandbox"}
          :keep-history?      true
          :schema-flexibility :write
          :index :datahike.index/hitchhiker-tree
          :initial-tx         schema})

(def cfg2 {:store              {:backend :mem
                                :id "sandbox2"}
           :keep-history?      true
           :schema-flexibility :write
           :index :datahike.index/hitchhiker-tree
           :initial-tx         schema})


(d/create-database cfg)
(d/create-database cfg2)

(def conn (d/connect cfg))
(def conn2 (d/connect cfg2))

(d/transact conn [{:name "Alice"
                   :age  25}
                  {:name "Bob"
                   :age  35}
                  {:name    "Charlie"
                   :age     45
                   :sibling [[:name "Alice"] [:name "Bob"]]}])

(d/transact conn [{:name "Daisy"
                   :age  21}])

(d/transact conn2 [{:name "Alice"
                    :age  25}
                   {:name "Bob"
                    :age  35}
                   {:name    "Charlie"
                    :age     45
                    :sibling [[:name "Alice"] [:name "Bob"]]}])

(d/transact conn2 [{:name "Donald"
                    :age  38}])


(d/q '[:find ?t
       :in $ $2
       :where
       [$ ?e ?a ?v ?t]
       [$2 ?e ?a ?v ?t]] @conn @conn2)