LINQ Join with Multiple From Clauses

Question

When writing LINQ queries in C#, I know I can perform a join using the join keyword. But what does the following do?

from c in Companies
from e          


        

Answer 1

All the first set of objects will be joined with all the second set of objects. For example, the following test will pass...

    [TestMethod()]
    public void TestJoin()
    {
        var list1 = new List();
        var list2 = new List();

        list1.Add(new Object1 { Prop1 = 1, Prop2 = "2" });
        list1.Add(new Object1 { Prop1 = 4, Prop2 = "2av" });
        list1.Add(new Object1 { Prop1 = 5, Prop2 = "2gks" });

        list2.Add(new Object2 { Prop1 = 3, Prop2 = "wq" });
        list2.Add(new Object2 { Prop1 = 9, Prop2 = "sdf" });

        var list = (from l1 in list1
                    from l2 in list2
                    select l1).ToList();

        Assert.AreEqual(6, list.Count);

    }