clojure.java.jdbc jsonb support for postgresql

jsonb_test.clj

(ns xxx.jsonb-test
  (:require
   [clojure.test :refer [deftest is use-fixtures]]
   [clojure.java.jdbc :as jdbc]
   [cheshire.core :as json]
   [xxx.db :as test-db :refer [*db*]])
  (:import
   [org.postgresql.util PGobject]
   [java.sql PreparedStatement]))

(use-fixtures :each test-db/fixture)

(extend-protocol jdbc/IResultSetReadColumn
 org.postgresql.util.PGobject
   (result-set-read-column [val _ _]
     (when (= "jsonb" (.getType val)) (json/parse-string (.getValue val) true))))

(extend-protocol jdbc/ISQLParameter
 clojure.lang.IPersistentMap
   (set-parameter [m ^PreparedStatement s ^long i]
     (.setObject s i (doto (PGobject.) (.setType "jsonb") (.setValue (json/generate-string m))))))

(deftest read-test (is (= {:a 5} (:val (first (jdbc/query *db* "select '{\"a\":5}'::jsonb as val"))))))

(deftest write-test
  (jdbc/execute! *db* "create table t (val jsonb)")
  (jdbc/insert! *db* :t {:val {:a 6}})
  (is (= {:a 6} (:val (first (jdbc/query *db* "select * from t"))))))