EntityFramework更新具有相关对象的实体

Question

I have a Project entity and a Rule entity. A project can have many rules.

Edit 1: Here is the relation we have defined. Sorry for not using plural in the navigation property, we haven't updated it yet.

So I have this method:

    public bool Update(Project project)
    {
        Logger.Log(GetType(), string.Format("Updating project {0}", project));
        using (var ctx = new EntityModelContainer())
        {

            if (project.Id == 0)
            {
                return false;
            }

            try
            {
                ctx.ProjectSet.Attach(project);
                ctx.Entry(project).State = EntityState.Modified;
                return ctx.SaveChanges() >= 1;
            }
            catch (Exception exc)
            {
                throw new ComplianceException(exc.Message, exc);
            }
        }
    }

It will update all scalar attributes of a project. But if I add or delete a rule to a project and run Update(project) , it is not considered. Why?

Edit 2: I have also tried to re-read the project and assign the updated values. Please notice that projectRead.Rule is a list.

    public bool Update(Project projectGiven)
    {
        // Add all changes here
        Project projectRead = this.ReadProject(projectGiven.Id);
        if (projectRead == null)
        {
            Logger.Log(GetType(), "Project not found");
            return false;
        }

        projectRead.ProjectName = projectRead.ProjectName;
        projectRead.Report = projectRead.Report;
        projectRead.Rule = projectRead.Rule;

        Logger.Log(GetType(), string.Format("Updating project {0}", projectRead));
        using (var ctx = new EntityModelContainer())
        {
            ...

Thank you very much!

Answer 1

Seems to me that with latest version of entity framework, and entity is not added automatically to the change tracker if assigned to and entity that is already in the change tracker.

Obviously this depends on the way role and project are related.

I suppose the more simple way si to create a procedure that reload the project including all the roles, delete the selected one from the list, and after to save it, at this point I think al the updates are done correrctly.

Answer 2

I solved the problem. I need to reload the project within the same context before I update.