-- Oracle: JSON_DATAGUIDE function 


SELECT 
  JSON_DATAGUIDE(qt.Ref_Numbers) JSON_DATAGUIDE_ 
FROM
(SELECT
  JSON_OBJECTAGG(
          KEY  ref_desc
          VALUE  ref_id)  Ref_Numbers
 FROM
   (SELECT
     level*10  ref_id,
     TO_CHAR(TO_DATE(level*10,'J'),'JSP') ref_desc 
    FROM  DUAL
    CONNECT BY level < 5
   )
) qt
;