Mysql error 1093 - Can't specify target table for update in FROM clause

UPDATE  table_name a,

  (SELECT

Clonum_name    s

   FROM table_name

   GROUP BY Clonum_name   

   HAVING COUNT(DISTINCT Cable_no) > 1) b

SET Clonum_name    = CONCAT(Clonum_name    ,'_',Cable_no)

WHERE a. Clonum_name    = b.s

Read more ...