For details, see http://pastebin.com/raw/1W88ywuu

The actual test:

    (defparameter *model*
      (make-model (cl-json:decode-json-from-source #P"/tmp/json.test")))

    (with-table (farmers :title "farmers"
                         :model *model*
                         :accessors ((farmer-name "Full name")
                                     (farmer-fruits "Fruits")))
      (dolist (farmer (table-entities farmers))
        (when (ppcre:scan "Bob" (farmer-name farmer))
          (with-table (fruits :title "fruits"
                              :model *model*
                              :accessors ((fruit-name "Name"))
                              :index t)
            (return
              (loop
                 for fid in (farmer-fruits farmer)
                 collect (fruit-name (iget fruits fid))))))))

The :accessors arguments is used to resolve field access once for all when visiting a table. If :index is true, we build a temporary hash-table based on identifiers.