public Grade_Info GetGradeCodeBySchoolCode(School_Info school_Info, string v)
 {
     if (school_Info == null)
     {
         return(null);
     }
     return(DbSet.FirstOrDefault(a => a.GradeCode.StartsWith(school_Info.SchoolCode) && a.GradeName == v));
 }
 public void Update(School_Info obj)
 {
     throw new NotImplementedException();
 }