How to limit a LINQ left outer join to one row

Question

I have a left outer join (below) returning results as expected. I need to limit the results from the \'right\' table to the \'first\' hit. Can I do that somehow? Currently,

Answer 1

Use an inner query. Include DefaultIfEmpty for the case of no photo and orderby for the case of more than one. The following example takes the photo with the greatest id.

var query = 
    from i in db.items
    let p = from p in db.photos where i.id == p.item_id orderby p.id select p).DefaultIfEmpty().Last()
    orderby i.date descending
    select new {
      itemName = i.name,
      itemID = i.id,
      id = i.id,
      photoID = p.PhotoID
    };

If you need to handle the case of no photo specially, you can omit DefaultIfEmpty and use FirstOrDefault/LastOrDefault instead.