UPDATE ENROLMENT_EVALUATION
   SET GRADE = CONCAT('TYPE20:', GRADE_VALUE)
 WHERE KEY_ENROLMENT IN(
SELECT CM.ID_INTERNAL
  FROM CURRICULUM_MODULE CM, DEGREE_MODULE DM
 WHERE DM.ID_INTERNAL = CM.KEY_DEGREE_MODULE
   AND DM.GRADE_SCALE = 'TYPE20')
   AND GRADE_VALUE IS NOT NULL;