public static List <SubscriptionDTO> getSubscriptionList()
 {
     using (Gymnastics_Studio_DataEntities GSDE = new Gymnastics_Studio_DataEntities())
     {
         List <Subscription> SubscriptionList = new List <Subscription>();
         SubscriptionList = GSDE.Subscriptions.ToList();
         return(SubscriptionDTO.ConvertListToDTO(SubscriptionList));
     }
 }
 public static List <SubscriptionDTO> getSubscriptionListByStudent(int studentId)
 {
     using (Gymnastics_Studio_DataEntities GSDE = new Gymnastics_Studio_DataEntities())
     {
         string studentKind = GSDE.Students.Where(x => x.Id == studentId).FirstOrDefault().StudentKind;
         List <Subscription> SubscriptionList = new List <Subscription>();
         SubscriptionList = GSDE.Subscriptions.Where(x => x.StudensKind == studentKind).ToList();
         return(SubscriptionDTO.ConvertListToDTO(SubscriptionList));
     }
 }