Update entities all at once

Question

I have a list of entities returned me from external service,
in this list i would take only item with flag IsNew setted to true and save in my database.
My code is:

var entitiesLst
=ExternalService("BoxIt");

        foreach (var item in entitiesLst )
        {
            if (item.IsNew == true) 
                context.BoxIt.Update(item);
        }
        context.SaveChanges();

But i would like to do avoiding use of foreach cycle, there is any way to do this?

Thanks

Answer 1

Well, you can simulate that you are not using a loop by using LINQ:

entitiesLst.Where(item => item.IsNew).ForEach(item => context.BoxIt.Update(item));

But note that, internally, LINQ will use a loop to implement this.

You can also use UpdateRange:

context.BoxIt.UpdateRange(entitiesLst.Where(item => item.IsNew));

But, again, the internal implementation for this method will actually use a loop.

Answer 2

You should be able to use AddRange of the DbContext e.g.

public static void ForumQuestion(List<CustomerItem> list)
{
    var resultList = list.Where(customer => customer.ContactTypeIdentifier == 9).ToList();
    using var context = new NorthwindContext();
    context.AddRange(resultList);
    context.SaveChanges();

}

Since I don't have your model these code samples use a model I have.

Note If not using C#9

public static void ForumQuestion(List<CustomerItem> list)
{
    var resultList = list.Where(customer => customer.ContactTypeIdentifier == 9).ToList();
    using (var context = new NorthwindContext())
    {
        context.AddRange(resultList);
        context.SaveChanges();
    }
}