Question

MVC3 and Entity framework newbie here. I’m trying to write a controller that will handle both edits and creating new entries. Here is my code so far (most of it auto generated)

    //POST: /License/Save
    [HttpPost]
    public string Save(LICENSE_USER license_user)
    {
        if (license_user.License_ID != 0)
        {
            if (ModelState.IsValid)
            {
                db.Entry(license_user).State = EntityState.Modified;
                db.SaveChanges();
                return "Save Complete";
            }
        }
        else
        {

            if (ModelState.IsValid) {
                db.LICENSE_USER.Add(license_user);
                db.SaveChanges();
                return "New License created - " + license_user.License_ID;
            }
        }
        return "What's going on here?";
    }

It works great for edits since I’m including the License_ID field in the POST. For new entries, however, I’m excluding the License_ID field and it defaults to 0. What’s the most elegant way to get the next License_ID field and updating the object with that field?

Answer 1

Make the License_ID column in your database a primary autoincrement key. This way you don’t need to set it manually when inserting a new entity. The database will take care.

In your EDMX model the StoreGeneratedPattern attribute must be set to Identity for this property.