SQL to get the Role's and user id's assigned to a permission list

SELECT   C.ROLEUSER AS USER_IDS, B.ROLENAME as ROLE
      FROM PSCLASSDEFN A, PSROLECLASS B, PSROLEUSER C
     WHERE A.CLASSID = B.CLASSID AND B.ROLENAME = C.ROLENAME AND A.CLASSID = 'PTPT1200'
     ORDER BY 1,2;