MVC模型 - 如何在DB中更新一行？

Question

I am new to MVC. I am adding into the database OK with this code:

    [HttpPost]
    [Authorize]
    public ActionResult Add(CourseModel course)
    {
        course.UserID = (Guid)Membership.GetUser().ProviderUserKey;

        _db.Class.Add(course);
        _db.SaveChanges();

        return View();
    }

But how do I correctly update a 'course' if I already have it in the DB, but the user updated one field?. I can delete it, and then read the updated one and that works OK but I'm pretty sure that is not the correct way of doing it.

Thank you.

Answer 1

Assuming you're using EF, to update a record in database. Using the following code

_db.Entry<Course>(course).State = System.Data.EntityState.Modified;
_db.SaveChanges();