Hi Greg.
FirstOrDefault() will return 0 for non null Ints, So I'm guessing that
t.Id is an (int).
So you're going to have to do something like this.
ListAB abs = new ListAB();
for (int i = 0; i 10; i++)
{
abs.Add(new AB { Id = i });
}
int? id = null;
IEnumerableint output = from t in abs where t.Id == 1000
select t.Id;
if(output.Any())
{
id = output.First();
}
Assert.IsNull(id);
or This.
public static int? FirstOrNull(this IEnumerableint query)
{
if (query.Any())
{
return query.First();
}
return null;
}
int? alternative = (from t in abs where t.Id == 1000 select
t.Id).FirstOrNull();
hth.
Davy,
The US Congress voted Pizza sauce a vegetable. Don't even try to convince
me of anything in the states is sane any more!
On Mon, Mar 4, 2013 at 11:20 AM, James Chapman-Smith
ja...@chapman-smith.com wrote:
Try this:
** **
int? id =
(from t in things where t.Name == Foo select t.Id)
.ToArray()
.Concat(new int?[] { null })
.First();
** **
Cheers.
** **
James.
** **
*From:* ozdotnet-boun...@ozdotnet.com [mailto:
ozdotnet-boun...@ozdotnet.com] *On Behalf Of *Greg Keogh
*Sent:* Monday, 4 March 2013 18:20
*To:* ozDotNet
*Subject:* LINQ select nullable Id
** **
Folks, I want to select the int Id of an entity in a DbSet, or int? null
if it's not found. Like this *wrong* sample:
int? id = (from t in things where t.Name == Foo select
t.Id).FirstOrDefault();
In this case I get int zero if there is no match but I want null. Is there
some way of rearranging this to get an Id or null? Remember that the query
has to convertible down to SQL.
Greg K
