AddOrUpdate does not modify children

问题

I am using AddOrUpdate in my seed method to keep my permissions up to date, however, in the situation where the below code is updating the existing role (rather than creating it), any new Permissions I created are not being added to the role. What am I doing wrong?

foreach (KeyValuePair<string, string[]> s in new Dictionary<string, string[]>{
                {"Superuser", context.Permissions.Select<Permission, string>(p=>p.Name).ToArray()},

            })
            {
                Role r = new Role();
                r.Name = s.Key;
                r.Permissions = new List<Permission>();
                foreach (string p in s.Value)
                    r.Permissions.Add(context.Permissions.Where(per => per.Name == p).First());

                context.Roles.AddOrUpdate(i => i.Name, r);
            }

context.SaveChanges();

回答1:

AddOrUpdate only adds or updates the main entity, but not its relations.

So you have to do it in two steps:

1. Create the Role, and AddOrUpdate it. Now you can get the RoleId (or whatever the PK is) form your added or updated Role.
2. Create the Permissions, and set explicitly their RoleId (or whatever the FK is). Then AddOrUpdate the Permissions.

来源：https://stackoverflow.com/questions/23067806/addorupdate-does-not-modify-children