Quickly model your tables with malli.provider/provide. Works well with JSON columns -- malli finds a specification that works with all your data.

(->> (with-open [conn (jdbc/get-connection db-datasource)]
         (jdbc.sql/query conn ["select * from myschema.mytable"]))
       (malli.provider/provide))
  [:map
   [:mytable/id int?]
   [:mytable/name string?]]