Unable to update database using savechanges() in Entity Framework

Question

I am trying the Model first approach of Entity Framework. I am a newbie to Entity Framework and learning from here and coded the same way. But I am getting this error

Unable to update the EntitySet 'Users' because it has a DefiningQuery and no <InsertFunction> element exists in the <ModificationFunctionMapping> element to support the current operation.

the code I am running is:

protected void Page_Load(object sender, EventArgs e)
    {

        User use = new User();
        use.First_Name = "Arslan";
        use.Last_Name = "Akbar";
        use.Password = "alone";
        use.Email = "arslan@gmail.com";
        use.Designation = "Head";
        using (CustomersEntities ce = new CustomersEntities())

        {

            //int count = ce.Users.Count();
            //count++;
           // use.Id = count;

            ce.Users.Add(use);
            ce.SaveChanges();
          //  ce.Users.Create(use);
          //  ce.SaveChanges();
            //ce.Entry(use).State = System.Data.EntityState.Added;

        }

    }

I am unable to identify the issue.

Does this table have a primary key, or is this a View. If its a view or it doesn't have a primary Key associated with it you will not be able to insert data into it. See this post http://stackoverflow.com/questions/7583770/unable-to-update-the-entityset-because-it-has-a-definingquery-and-no-updatefu — Bearcat9425, Nov 12 '13 at 14:20
yes this table has primary key named ID and this is not a view,Primary key is auto increment. — Naveed Yousaf, Nov 12 '13 at 14:23
i added this new line `use.Id = 6;` just below the `use.Designation` but still getting the same error. — Naveed Yousaf, Nov 12 '13 at 14:26
I am not sure, but you can try to replace: `User use = new User();` With: `User use = ce.Users.Create();` When `ce` is the `DbContext` — RE6, Nov 12 '13 at 16:47

Shiraz Bhaiji · Accepted Answer · 2013-11-12T20:47:04.680

0

There are a number of things that could be causing this, some are covered in comments above:

Trying to update a view
Trying to update a table that does not have a primary key
The primary key was added to the table directly, not via model first, the C# code therefore does not see the primary key
There is a reference to another table and there are some problems with the keys

I would take a backup, delete what you have and then try again from scratch.

PS: I just worked through the example in your link, it worked fine for me.

What I noticed was that the Add method was "AddObject" not "Add". You should check the target framework for your project.

edited Nov 12 '13 at 20:47

answered Nov 12 '13 at 19:56

Shiraz Bhaiji

64,065
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I just did not make Id as a primary key.The procedure is that i just created that primary key deleted the table from Model then again imported them now it's working fine. – Naveed Yousaf Nov 13 '13 at 05:13

score -1 · Answer 2 · answered Aug 28 '19 at 05:27

-1

Database table doesn't have a primary key, in your data base set primary key for user table.

answered Aug 28 '19 at 05:27

behnam shateri

1,223
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Unable to update database using savechanges() in Entity Framework

2 Answers2