foreach loop not working correctly when to save copy of entity in MVC with entity framework

Question

I have MVC3 project where I use Entity Framework I have entity with player that user should be able to make copy of.

To make a copy of player I have the following in my repository:

public Player CreateTemplate(Player player)
    {
        var copy = new Player();

        copy.Birth_Date = player.birth_Date;
        copy.Comment = player.Comment;
        copy.Name = player.Name;
        copy.Agent = player.Agent;
        copy.AgentId = player.AgentId;
        foreach (SelectedTeams selectedTeams in player.SelectedTeams.ToList())
        {
            var copyselectedteams = new SelectedTeams();
            copyselectedteams = selectedTeams;
            copy.SelectedTeams.Add(copyselectedteams);
        }
        db.AddToPlayer(copy);
        db.SaveChanges();
        return copy;
    }

The problem for me is, that once my foreach starts looping, my original player lose it's SelectedTeams Is there any solutions is for this problem?

Thanks in advance

possible duplicate of How to Clone the Entity object and all of its associated entities values aswell with EF in MVC — Darin Dimitrov
– Darin Dimitrov, Commented May 10, 2012 at 9:42
SelectedTeams as class name and collection name, very confusing! Do you want to copy the SelectedTeams's as well, or only copy the references? — Gert Arnold
– Gert Arnold, Commented May 10, 2012 at 10:40

lucask · Accepted Answer · 2012-05-10 11:21:16Z

1

Do You have Lazy Loading disabled by any chance? You may try to eager load entity like this:

var firstPlayer = dbContext.Players.Include("SelectedTeams").FirstOrDefault<Player>(p => p.PlayerId == 1);
var copiedPlayer = repo.CreateTemplate(firstPlayer);

Also You shouldn't copy references of existing entities to new entity.

copyselectedteams = selectedTeams;

Instead copy its properties (except relationship keys of course or You will get exceptions).

answered May 10, 2012 at 11:21

lucask

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Comments

usr · Accepted Answer · 2012-05-10 10:53:56Z

1

You are overwriting the reference to the new object you just created:

var copyselectedteams = new SelectedTeams(); //overwritten...
copyselectedteams = selectedTeams; //...here

answered May 10, 2012 at 10:53

usr

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1 Comment

Obsivus Over a year ago

Could you give an example on how to not overwrite and instead pass the reference to the new object so the original object wont get affected by the override

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