DbUpdateException when adding and saving record to DbContext in ASP.net MVC

Question

I am trying to add a Cart record into my class ProjectConext which is of type DbConext. The problem is that when I Add the record and try to save it, I get the error that the CustomerID field cannot be null (which it can't), even though as far as I can see I am inserting a non-null value for it. Here is my code for the Model:

    public class ShoppingCart
{
    ProjectContext _db = new ProjectContext();

    public void AddToCart(Video toAdd, Customer CurUser)
    {
        var CartItem = new Cart
        {
            CustomerID = CurUser.CustomerID,
            Item = toAdd.Title,
            Count = 1,
            Price = 1.00
        };
        _db.Carts.Add(CartItem);
        _db.SaveChanges();
    }
}

I inserted a breakpoint at the line after the Add() and I can see that CartItem has all fields filled, and _db.Carts is MVCProject.Model.Cart as it should be. If anyone has an idea of why this is not adding the record correctly your help would be greatly appreciated. Thanks in advance.

Can you post what your CartItem entity looks like? Specifically, the configuration. — Jeff S
– Jeff S, Commented Jan 31, 2013 at 2:23
The inner exception I am getting is:"Cannot insert the value NULL into column 'CustomerID', table 'Azim.dbo.Carts'; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated." My Cart looks like this:namespace MVCVideoProject.Models { public class Cart { [Key] public int CustomerID { get; set; } public string Item { get; set; } public int Count { get; set; } public double Price { get; set; } } } — user1985569
– user1985569, Commented Jan 31, 2013 at 13:50
Sorry about the formatting. I can see in my breakpoint after the Add() line that the record does in fact get inserted into my DbContext, so I don't understand why it is giving me this error. — user1985569
– user1985569, Commented Jan 31, 2013 at 13:51

user1985569 · Accepted Answer · 2013-01-31 14:13:58Z

1

I found the answer, the problem was that since CustomerID was an identity column in the Cart table, it was trying to automatically insert a value which erased the existing. Adding the code: DatabaseGenerated(DatabaseGeneratedOption.None)

as in

    public class Cart
{
    [Key, Required, DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int CustomerID { get; set; }
    public string Item { get; set; }
    public int Count { get; set; }
    public double Price { get; set; }
}

Solved the problem.

answered Jan 31, 2013 at 14:13

user1985569

2023 silver badges10 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

DbUpdateException when adding and saving record to DbContext in ASP.net MVC

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related