is this LINQ save function acceptable? (to have a shared INSERT/UPDATE logic like this?) looking for feedback...

Question

Hey guys, new to WPF and really struggling with 'the right way' to do things...

public void Save(CompanyContact entityToSave)
{
  try
  {

    var saveEntity = (from cc in db.CompanyContacts
        where cc.CompanyContactId == entityToSave.CompanyContactId
        select cc).SingleOrDefault();

    if (saveEntity == null)
    {
      //INSERT logic                    
      entityToSave.CreatedById = new CompanyPersonRepository().GetCompanyPerson(DataContext.Default.LoginUsername).CompanyPersonId;
      entityToSave.ModifiedById = entityToSave.CreatedById;

      db.CompanyContacts.InsertOnSubmit(entityToSave);
      db.CompanyContacts.Context.SubmitChanges();
    }
    else
    {
      //UPDATE logic            
      saveEntity.ModifiedById = new CompanyPersonRepository().GetCompanyPerson(DataContext.Default.LoginUsername).CompanyPersonId;
      saveEntity.CompanyId = entityToSave.Company.CompanyId;
      saveEntity.FirstName = entityToSave.FirstName;
      saveEntity.LastName = entityToSave.LastName;
      saveEntity.CompanyContactTypeId = entityToSave.CompanyContactTypeId;

      db.CompanyContacts.Context.SubmitChanges();

    }

...

if not can you please provide some comments on why it is not, or provide an example of a better way to write LINQ functions if I am not on the right path?? (thanks)

Answer 1

Hey,

That would work; you can also store the record in the form as a variable, and if its null, the record doesn't exist, but if it does, an update needs to occur. That way, you can minimize your queries, and you can simply assign form values to one object rather than dealing with two.

Alternatively, if you bind a LINQ object to the form, since it implements INotifyPropertyChanged, any changes are immediately bound to the object if you setup the bindings within the form and assign the object as the datacontext.

HTH.