Left join in Linq?

Question

There are a lot of questions on SO already about Left joins in Linq, and the ones I\'ve looked at all use the join keyword to achieve the desired end.

T

Answer 1

What are you talking about? That from i in c.Invoice.DefaultIfEmpty() is exactly a left join.

        List strings = new List() { "Foo", "" };

        var q = from s in strings
                from c in s.DefaultIfEmpty()
                select new { s, c };

        foreach (var x in q)
        {
            Console.WriteLine("ValueOfStringIs|{0}| ValueOfCharIs|{1}|",
                x.s,
                (int)x.c);
        }

This test produces:

ValueOfStringIs|Foo| ValueOfCharIs|70|
ValueOfStringIs|Foo| ValueOfCharIs|111|
ValueOfStringIs|Foo| ValueOfCharIs|111|
ValueOfStringIs|| ValueOfCharIs|0|