LINQ - Full Outer Join

Question

I have a list of people\'s ID and their first name, and a list of people\'s ID and their surname. Some people don\'t have a first name and some don\'t have a surname; I\'d l

Answer 1

As you've found, Linq doesn't have an "outer join" construct. The closest you can get is a left outer join using the query you stated. To this, you can add any elements of the lastname list that aren't represented in the join:

outerJoin = outerJoin.Concat(lastNames.Select(l=>new
                            {
                                id = l.ID,
                                firstname = String.Empty,
                                surname = l.Name
                            }).Where(l=>!outerJoin.Any(o=>o.id == l.id)));