Question

I have a small question. How do i make linq aware that some columns are uniqe

fx. I have a table, with columns “ID” and “Name”

ID is auto incrementing Primary key. Name is just varchar(255)

The result of a linq like this:

from item in db.ItemSet
where item.ID == 1
select item

Im left with a IQueryable. But there can be only 1 item, with “ID”==1
How do i tell linq this.

At the moment i do this

(from item in db.ItemSet
 where item.ID == 1
 select item).First()

But I would consider this a “hack”…

Answer 1

You could use .Single() instead of .First().

However, both of those assume that the record exists and will throw an exception if no record is found. If there’s a potential for looking up a record that does not exist, you may want to consider .FirstOrDefault() / .SingleOrDefault().

Further reading:

• CodeProject article
• MSDN post