public void Delete(int num_matricula)
 {
     using (GlobalDbContext dbContext = new GlobalDbContext())
     {
         Alumno alumno = dbContext.Alumnos(true)
                         .Where(s => s.Num_Matricula == num_matricula)
                         .FirstOrDefault();
         if (alumno != null)
         {
             dbContext.Remove(alumno);
             dbContext.SaveChanges();
         }
     }
 }
        public void Update(int num_matricula, int dni, string nombre)
        {
            using (GlobalDbContext dbContext = new GlobalDbContext())
            {
                Alumno alumno = dbContext.Alumnos(true)
                                .Where(s => s.Num_Matricula == num_matricula)
                                .FirstOrDefault();
                if (alumno != null)
                {
                    alumno.Dni    = dni;
                    alumno.Nombre = nombre;

                    dbContext.SaveChanges();
                }
            }
        }
        public List <Alumno> GetAlumnos(string buscarText)
        {
            using (GlobalDbContext dbContext = new GlobalDbContext())
            {
                IQueryable <Alumno> query = dbContext.Alumnos();
                if (!string.IsNullOrEmpty(buscarText))
                {
                    query = query.Where(c =>
                                        c.Nombre.Contains(buscarText)
                                        );
                }

                query = query.OrderBy(alumno => alumno.Nombre);
                return(query.ToList());
            }
        }