Error: 
SQL: SELECT CLE.CourseLevelId, CLE.CLE_Name_Short, COUNT(*) AS aantal FROM T_CourseLevel CLE, DocumentSuperLevel DSL WHERE CLE.FK_SuperLevelId = 4 AND CLE.CLE_public = 'Yes' AND CLE.FK_SuperLevelId = DSL.FK_SuperLevelId GROUP BY CLE.CourseLevelId ORDER BY CLE.CLE_Name