Linq 2 SQL : update record via a web service

Question

I have a business class. In this business class there are :

a context to access database (via .dbml)
Some methods

A SaveUser(User user) method from this business class is called by a webservice. This method receive the modified User object. How can I update the record in the database by the value from the object receive as parameter (the fields value have the expected values) ?

I tried this :

context.Users.Attach(user); 
context.SubmitChanges();

I tried without the last line, same... no change in the database.

Any idea ?

Thanks,

Update 1

public class RightManager
    {
        private readonly DBDataContext dc;

        public RightManager()
        {
            dc = new DBDataContext();
        }

        public User GetUser(int id)
        {
            User user = dc.GetTable<User>()
                .Where(x => x.Id == id && x.IsEnable == true)
                .SingleOrDefault<User>();

            return user;
        }                     

        public void SaveUser(User user)
        {
            dc.Users.Attach(user);
        }

    }

Some code would be welcome, we can't really see what you're doing wrong without seeing the code. — Aidiakapi, Sep 08 '11 at 11:03
Please see this related question: http://stackoverflow.com/q/1758214/31136 — bruno conde, Sep 08 '11 at 11:29

score 1 · Accepted Answer · answered Sep 08 '11 at 11:08

Sure, the object you recieve by argument is not User object. You have to get one from context (usually by Id), update required properties and submit then.

public void SaveUser (User user) {
    var userToUpdate = context.Users.Where(u => u.Id == user.Id).Single();
    userToUpdate.FirstName = user.FirstName;
    userToUpdate.LastName = user.LastName;

    context.SubmitChanges();
}

score 0 · Answer 2 · answered Sep 08 '11 at 11:13

0

You can use one of the overload of the attach method.

See this post: http://blogs.msdn.com/b/dinesh.kulkarni/archive/2007/10/08/attach-if-you-have-something-detached.aspx

answered Sep 08 '11 at 11:13

Stéphane Bebrone

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Linq 2 SQL : update record via a web service

2 Answers2