public string SearchByClass(string jsonValue)
 {
     IClassTableModal modal = Serializer.GetDeserialized<ClassTableModal>(jsonValue);
         ClassAccessLayer al = new ClassAccessLayer(modal);
         IClassTableModal resultModal = al.SelectClassById(Constants.SP_SelectClassId);
         StudentAccessLayer sl = new StudentAccessLayer();
         StudentCollection ouput = sl.GetStudentByClass(Constants.SP_SearchByClass, resultModal);
         return Serializer.GetSerialized<StudentCollection>(ouput);
 }
 public string SelectClassTable()
 {
     ClassAccessLayer al = new ClassAccessLayer();
     ClassCollection output = al.SelectClass(Constants.SP_SelectClassTable);
     return Serializer.GetSerialized<ClassCollection>(output);
 }