More efficient way to do multiple queries in the Entity Framework with SQLite?

Question

I currently am using the Microsoft Entity Framework to handle my db. I need to be able to reset one column of a table in my db somewhat quickly, and the way I am doing it right now takes quite a while and blocks up the application during the loop. This is the current code:

using (var db = new DbContext())
{
    var userRepo = new UserRepository(db);
    User[] users = userRepo.GetAll().ToArray();
    foreach (User user in users)
    {
        if (user.Money != 0)
        {
            user.Money = 0;
            db.Set<User>().Update(user);
            await db.SaveChangesAsync();
        }
    }
}

I have checked by console logging during the loop to see the speed of each change, and it is very slow considering I have hundreds of users. Is there a way to just do a normal query to set all data in one column to something with the Entity Framework?

Answer 1

As @GertArnold mentioned in his comment, there is a 3rd party library called EntityFramework.Extended that lets you do a batch to update a set of specific rows. In your case it would be:

db.Set<User>().Update(u=>new User{Money=0});
await db.SaveChangesAsync();

Just install this nuget package and execute the code I show above.