SELECT A.*,B.CourseName,B.CourseFeature,D.TeacherName,IFNULL(D.TeacherHead,'') AS TeacherHead,E.SName AS SchoolName,R.RoomName
,IFNULL(t.GuestNum,0) AS OrderStudentCount,IFNULL(B.SellPrice,0) AS CourseSellPrice,IFNULL(B.OriginalPrice,0) AS CourseOriginalPrice ,B.B2CRatio,B.B2CReNewRatio,B.B2BRebateRatio,B.B2BReNewRatio,B.SchoolRebateRatio,B.SchoolReNewRatio
,IFNULL(t.GuestNum,0) AS OrderStudentCount,IFNULL(B.SellPrice,0) AS CourseSellPrice,B.SellPriceType as CourseSellPriceType,IFNULL(B.OriginalPrice,0) AS CourseOriginalPrice ,B.B2CRatio,B.B2CReNewRatio,B.B2BRebateRatio,B.B2BReNewRatio,B.SchoolRebateRatio,B.SchoolReNewRatio
,B.CourseSubject,IFNULL(csubject.SubjectName,'') AS CourseSubjectName
FROM rb_class AS A LEFT JOIN rb_course AS B ON A.CouseId=B.CourseId