Entity Framework update record not working

Question

I'm new to Entity Framework. I'm trying to update a record and save changes to the database.

public void SaveEdit(Gate gate)
        {
            try
            {
                using (dc = new GateEntities())
                {
                    var query = (from tbsite in dc.tblSites
                                 where tbsite.ID == gate.ID
                                 select tbsite).FirstOrDefault();

                    query.CalledInAt = gate.CalledInAt;
                    query.CallerRequest = gate.CallerRequest;
                    query.ContactPersonOnSite = gate.ContactPersonOnSite;
                    query.Email = gate.Email;
                    query.EmailSitePerson = gate.EmailSitePerson;

                    dc.SaveChanges();
                }
            }
            catch (Exception ex)
            {

                throw ex;
            }



        }

It gets no exceptions or error messages but it does not save the changes to the database. why it's not updating the record?

Answer 1

After You modify query object You should change it's state to Modified before calling context.SaveChanges(). Your context object should know about the entity that You modify. Assuming dc is Your context object:

query.CalledInAt = gate.CalledInAt;
//change other properties ..
dc.Entry(query).State = EntityState.Modified;
dc.SaveChanges();

That should work for You.

Answer 2

You have to use the entityframework to select your object, with that the result object will be track-able, so try this

            using (var dc = new GateEntities())
            {
                var gate = dc.tblSites.Where(g => g.ID == date.ID).FirstOrDefault();

                gate.CalledInAt = gate.CalledInAt;
                gate.CallerRequest = gate.CallerRequest;
                gate.ContactPersonOnSite = gate.ContactPersonOnSite;
                gate.Email = gate.Email;
                gate.EmailSitePerson = gate.EmailSitePerson;

                dc.SaveChanges();
            }