无法使用实体框架保存记录

Question

My objects will not save no matter what I do they will fetch and get info and make a new record but not update.

This is the code that details with getting existing patient and then modifying the record setting the state then calling save change this is cracking my head the last three hours what is going wrong. I was told you had to change the entity state of an object before it would no if to save but when i try to attach it it says its already attached

Appointment _appointment = new Appointment();
int errorCount = 0;

Patient _patient = SourceDal.getPatientByPatientNewId(Convert.ToInt32(txtPatientId.Text));

_patient.SSN = txtSSN.Text;
_patient.FirstName = txtPatientFirstName.Text;
_patient.LastName = txtPatientLastName.Text;
_patient.Middle = txtPatientMiddle.Text;
_patient.AddressOne = txtPatientAddressOne.Text;
_patient.City = txtPatientCity.Text;
_patient.State = txtPatientState.Text;
_patient.ZipCode = txtPatientZip.Text;

_patient.HomePhone = txtPatientHomePhone.Text;
_patient.WorkPhone = txtPatientWorkPhone.Text;
_patient.CellPhone = txtPatientCellPhone.Text;

if (rBtnHomePhone.Checked == true)
    //   _patient.ApptPhone = txtPatientHomePhone.Text;

if (rBtnHomePhone.Checked == true)
    //   _patient.ApptPhone = txtPatientHomePhone.Text;

if (rBtnWorkPhone.Checked == true)
    // _patient.ApptPhone = txtPatientWorkPhone.Text;

_patient.BirthDate = dtBirthDate.DateTime;
_patient.emailAddress = txtPatientEmail.Text;
_patient.Race =   Convert.ToInt32(dpRace.SelectedValue);
_patient.Ethnicity =Convert.ToInt32(dpEthnicity.SelectedValue);
_patient.Language =  Convert.ToInt32(dpLanguages.SelectedValue);

if (dpGender.Text == "")
{
    dpGender.Focus();
    errorCount = 1;
    lblGenderRequired.Text = "* Gender is required.";
}
else
{
    errorCount = 0;
    lblGenderRequired.Visible = false;
}

_patient.Gender = "M";
_patient.PatientID = txtPatientId.Text;

SourceDal.SourceEntities.Patients.Attach(_patient);
SourceDal.SourceEntities.Patients.Context.ObjectStateManager.ChangeObjectState(_patient, EntityState.Modified);
SourceDal.SourceEntities.SaveChanges();

The error I get is

An unhandled exception of type 'System.InvalidOperationException' occurred in System.Data.Entity.dll

Additional information: An entity object cannot be referenced by multiple instances of IEntityChangeTracker.

Edit 2 :

Code to show my function getPaitnetByPatineyNewId

    public Patient getPatientByPatientNewId(int newId)
    {
        Patient patient = new Patient();

        if (newId == -1)
        {
            patient = new Patient();
        }
        else
        {
            patient = SourceEntities.Patients
                                    .Where(w => w.ID == newId)
                                    .FirstOrDefault();
        }

        return patient;
    }

Answer 1

I think you have some issues with proper separation of concerns within your DAL, but for the short solution, you should only add (and not attach) if it's a new entity

if (_patent.PatentId == 0)
{
    _patient.PatientID = txtPatientId.Text; // If you're using an identity column, remove this line. I would also strongly suggest not letting the user change this...
    SourceDal.SourceEntities.Patients.Add(_patient);
}

Answer 2

For Anyone else the above scenarios did not work for me so this is what I had to do. I put a flag on my forms isUpdate and check that on the save button then if save call similar to below then if add just call savechanges and its now working thank you for everyone help hope this help someone.

public void SaveProviders(Provider _providers)
{
  try
    {


            using (var ctx = new SMBASchedulerEntities(this.Connectionstring))
            {
                ctx.Providers.Add(_providers);
                ctx.Entry(_providers).State = System.Data.Entity.EntityState.Modified;
                ctx.SaveChanges();
            }
        }


        catch (DbEntityValidationException e)
        {
            foreach (var eve in e.EntityValidationErrors)
            {
                Console.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
                    eve.Entry.Entity.GetType().Name, eve.Entry.State);
                foreach (var ve in eve.ValidationErrors)
                {
                    Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
                        ve.PropertyName, ve.ErrorMessage);
                }
            }
            throw;
        }

    }