Entity Framework inserting new rows instead of updating them

Question

I have a problem when I am updating data to database. When I want to update data, Entitiy Framework adds new rows to tables that can have multiple rows (tables that have foreign key).

Database model:

Database model

When I update Phone/Contact or Tags entity, Entity Framework automatically adds new row instead of updating it

Here is code that I used:

public string UpdateContact(Contact contact)
{
    if (contact != null)
    {

        int id = Convert.ToInt32(contact.id);
        Contact Updatecontact = db.Contacts.Where(a => a.id == id).FirstOrDefault();
        Updatecontact.firstname = contact.firstname;
        Updatecontact.lastname = contact.lastname;
        Updatecontact.address = contact.address;
        Updatecontact.bookmarked = contact.bookmarked;
        Updatecontact.city = contact.city;
        Updatecontact.notes = contact.notes;
        Updatecontact.Emails1 = contact.Emails1;
        Updatecontact.Phones1 = contact.Phones1;
        Updatecontact.Tags1 = contact.Tags1;
        db.SaveChanges();
        return "Contact Updated";

    }
    else
    {
        return "Invalid Record";
    }
}

EDIT:

Here is EF Model code:

Contact:

public partial class Contact
{
    public Contact()
    {
        this.Emails1 = new HashSet<Email>();
        this.Phones1 = new HashSet<Phone>();
        this.Tags1 = new HashSet<Tag>();
    }

    public int id { get; set; }
    public string firstname { get; set; }
    public string lastname { get; set; }
    public string address { get; set; }
    public string city { get; set; }
    public Nullable<byte> bookmarked { get; set; }
    public string notes { get; set; }

    public virtual ICollection<Email> Emails1 { get; set; }
    public virtual ICollection<Phone> Phones1 { get; set; }
    public virtual ICollection<Tag> Tags1 { get; set; }
}

Emails/Tags and Phone have same model (with different name for value)

public partial class Email
{
        public int id { get; set; }
        public int id_contact { get; set; }
        public string email1 { get; set; }

        public virtual Contact Contact1 { get; set; }
}

well, you're not really loading in the Emails1/Phones1/Tags1 objects, but setting them to new instances of them that are being passed in as parameters...since you can have many, then it's just assuming you want to create new ones with new id's — beauXjames
– beauXjames, Commented Dec 30, 2014 at 19:21

Wiktor Zychla · Accepted Answer · 2014-12-30 19:47:25Z

7

Update properties rather than set new objects.

  Updatecontact.Emails1.email1 = contact.Emails1.email1;
  Updatecontact.Phones1.number = contact.Phones1.number;
  Updatecontact.Tags1.tag1 = contact.Tags1.tag1;

Edit: seems that your contact model has lists of emails, phones and tags. If this is so, then simple assignment won't work. Instead, when sent from the client, you have to find one-by-one and update:

 foreach ( var email in contact.Emails1 )
 {
     // first make sure the object is retrieved from the database 
     var updateemail = Updatecontact.Emails1.FirstOrDefault( e => e.id == email.id );
     // then update its properties
     updateemail.email1 = email.email1;
 }

 // do the same for phones and tags

edited Dec 30, 2014 at 19:47

answered Dec 30, 2014 at 19:18

Wiktor Zychla

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7 Comments

jureispro Over a year ago

Problem is that I contact.Emails1.email1 is not definied. I can't access it. Do I need to update my model?

Wiktor Zychla Over a year ago

Not defined means a compile time issue or a NullReferenceException?

Corey Adler Over a year ago

I think OP means that they are collections, not just individual properties.

jureispro Over a year ago

I updated my post @WiktorZychla . When I was creating model I auto-generate it using ADO.NET EF model.

Wiktor Zychla Over a year ago

@IronMan84: seems so, will address that in my answer.

|

Corey Adler · Accepted Answer · 2014-12-30 19:34:53Z

2

It's doing that because you're setting the different HashSet values to the values of a completely different collection, namely from what you call contact in that method. In order for you to properly do an update, you're going to have to loop through the emails, phones, and tags to check if those need to be added/updated/deleted on the actual object that you're trying to update.

answered Dec 30, 2014 at 19:34

Corey Adler

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1 Comment

jureispro Over a year ago

what if I update data in Contact table and modify foreign keys to CASCADE delete on update? After that I just insert data to tables like tags/emails and phones?

d219 · Accepted Answer · 2022-05-25 18:28:01Z

2

First, why do you have to search for the contact if you are already receiving it by parameter? That makes me think that you are creating a new one because you are in a different context, if so, then it creates a new record because you have 2 different object in 2 different context.

Try using just one object in the same context to update, EF should mark the object to modification by itself, if not then try making sure before saving that your object has EntityState.Modified.

edited May 25, 2022 at 18:28

d219

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answered Dec 30, 2014 at 19:35

GGAle

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2 Comments

jureispro Over a year ago

so I just save contacts to database and run db.SaveChanges() ?

GGAle Over a year ago

Yes, EF will take care of it

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