Query con sub-query in MySQL

[123delphi321]

prova a fare cosi: ....Cast(INTEGER as char)

SELECT gm.idstMember
FROM core_group_members gm
JOIN core_group g on g.idst = gm.idst
JOIN core_user cu ON cu.idst = gm.idstMember
where g.groupid = CONCAT('/oc_', cast((SELECT id_dir from core_org_chart WHERE translation='Addetti')) AND cu.valid as char) > 0