使用Entity Framework在单个Button中单击将数据插入两个不同的表中，在c＃中单击

Question

In my database I've 2 tables Employee and Address. In forms a single tab represents the fields of both tables. Under the click event of OK button i tried to insert the data but Exception occurred. I'am able to insert the data one table at a time but not both.

I'm having exception:

"an object with the same key already exists in ObjectStateManager. The existing object is in Modified state. An object can only be added to the ObjectStateManager if it is in the Added State."

My code is:

        try
        {

            using (TransactionScope ts = new TransactionScope())
            {
                db.Connection.Open();

                string empid = txtEmpId.Text.ToString();

                Employee emp = db.Employees.Single(a => a.Emp_ID == empid);

                emp.Full_Name = txtFullName.Text;

                db.AddToEmployees(emp);

                db.SaveChanges();

                Address address = db.Addresses.Single(b => b.Emp_Id == empid);

                address.House_No = txtHouseNo.Text.ToString();

                db.AddToAddresses(address);

                db.SaveChanges();


                ts.Complete();

                MessageBox.Show("completed successfully");
            }
        }

        catch (Exception e1)
        {
            MessageBox.Show(e1.Message);
        }

        finally
        {
            if (db.Connection.State == ConnectionState.Open)
            {
                db.Connection.Close();
            }
        }

Pl z help me out!

Answer 1

By the looks of your posted code, you retrieve an address from the database, update it, but then try to add it back into the database?

This causes a primary key conflict since the record cannot be inserted twice.

Remove the line which adds the address to the database, since it is already in there.

Answer 2

You can Use Transactions for inserting into the two tables as one SQL statement

Transaction Example