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c#sql-serverasp.net-mvcentity-frameworkef-code-first

C# Entity Framework Code-First- How do you add a row with foreign key using just the id of that foreign key?


If I have the following classes (using CodeFirst Entity Framework):

public class Notifications
{
    [Key]
    public int ID { get; set; }
    public virtual ClientDetails Client { get; set; }
    public virtual NotificationTypes NotificationType { get; set; }
    public virtual NotificationFreqs Frequency { get; set; }
    public virtual NotificationStatus Status { get; set; }
    public DateTime SendDate { get; set; }
    public DateTime? SentDate { get; set; }
    public DateTime QueueDate { get; set; }
}

public class NotificationFreqs
{
    [Key]
    public int ID { get; set; }
    [MaxLength(25)]
    public string Name { get; set; }
}

public class NotificationStatus
{
    [Key]
    public int ID { get; set; }
    [MaxLength(25)]
    public string Status { get; set; }
}

When adding a new notification, whats the most efficient way to say notification.status = 1 ? Do I have to query the DB each time to get the list available?

var notification = new Notifications();

var notificationType = db.NotificationTypes.FirstOrDefault(n => n.ID == notificationTypeId);
var notificationFreq = db.NotificationFreqs.FirstOrDefault(n => n.Name == setting.Value);

notification.NotificationType = notificationType; // Works
notification.Frequency = notificationFreq; // Works
notification.Status = new NotificationStatus { ID = 1 };  // Obviously doesn't work

I feel like hitting the DB this many times is inefficient but I do want these values normalized and in the db.

Any suggestions or is the way I'm doing NotificationType & Frequency the only way?

Thanks!


Solution

  • You have to fix your class. Add Id fields:

    public class Notifications
    {
        [Key]
        public int ID { get; set; }
        public virtual ClientDetails Client { get; set; }
    
        [ForeignKey("NotificationType")]
        public int? Type_ID  { get; set; }
        public virtual NotificationTypes NotificationType { get; set; }
    
        [ForeignKey("Frequency")]
        public int? Frequency_ID { get; set; }
        public virtual NotificationFreqs Frequency { get; set; }
    
        [ForeignKey("Status")]
        public int? Status_ID { get; set; }
        public virtual NotificationStatus Status { get; set; }
    
        public DateTime SendDate { get; set; }
        public DateTime? SentDate { get; set; }
        public DateTime QueueDate { get; set; }
    }
    

    in this case:

    notification.Type_ID = notificationTypeId; 
    notification.Frequency_ID = notificationFreq.ID; 
    notification.Status_ID = 1