Entity Framework recreating new record

Question

i have this scenario when creating a new record it also recreates it's association.

User newUser = new User();
newUser.UserGroupID = 1;
newUser.UserGroup = UserGroup.Find(1);

using (InventorySystemEntities context = new InventorySystemEntities(new ConfigurationManager().ConnectionString))
{
    context.Users.Add(newUser);
    context.SaveChanges();
}

when i save it, it creates a new User record, and so is a new UserGroup record.

Answer 1

You are using different contexts for UserGroup.Find() and Users.Add() this is not okay - use the same context for both and it will work fine.

using (InventorySystemEntities context = new InventorySystemEntities(new ConfigurationManager().ConnectionString))
{
    var newUser = new context.Users.CreateNew();
    newUser.UserGroup = context.UserGroup.Find(1);

    context.Users.Add(newUser);
    context.SaveChanges();
}

Answer 2

you need to tell the context that your entity is an existing entity:

User newUser = new User();
newUser.UserGroupID = 1;
newUser.UserGroup = UserGroup.Find(1);

using (InventorySystemEntities context = new InventorySystemEntities(new ConfigurationManager().ConnectionString))
{
    context.UserGroups.Attach(newUser.UserGroup);
    context.Users.Add(newUser);
    context.SaveChanges();
}

Answer 3

This is the same issue as in this question . Either use the same context for Find and SaveChanges, or, if that can't be done for some reason, use Attach() to attach the found UserGroup to the new context.