Question

I am writing code first Entity Framework app using POCO.
Here is simplified version:

I defined this entity:

public class Respondent
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int RespondentId { get; set; }

    [Display(Name = "Your Name")]
    public string Name { get; set; }
}

This entity is used to create a table:

public class MyContext : DbContext
{
    public DbSet<Respondent> Respondents { get; set; }
}

I also defined a View Model that contains this entity:

public class SurveyModel
{
    public Respondent Respondent { get; set; }
}

Now, in code:

var survey = new SurveyModel();
survey.Respondent = new Respondent();

When I need to write to the DB:

private MyContext db = new MyContext();

// HERE, after this line, SHOULD survey.Respondent.RespondentId be +1 ??
// Or only when I call db.SaveChanges() ??
db.Respondents.Add(survey.Respondent); 

At this moment survey.Respondent.RespondentId must be increased by 1 since it is defined as IDENTITY using the corresponding attribute.

But it doesn’t happen.
Please advice what I am doing wrong?
Thank you.

Answer 1

You need to call db.SaveChanges() in order for it to be saved to the database.