Question

The following code takes a collection of class C and creates a collection consisting of the values of two properties A and B. A and B are put inside the same collection:

class A
{
    public int x { get; set; }
}
class B
{
    public int x { get; set; }
}
class C
{
    public A A { get; set; }
    public B B { get; set; }
}

..........

var items = new List<C>()
                {
                    new C()
                        {
                            A = new A() {x = 1},
                            B = new B() {x = 2}
                        },
                    new C()
                        {
                            A = new A() {x = 3},
                            B = new B() {x = 4}
                        },
                };

var qA = from item in items
         select (object)item.A;
var qB = from item in items
         select (object)item.B;
var qAll = qA.Concat(qB);

Is it possible to do this with one query?

Answer 1

If you really want to flatten properties like that, you can feed arrays to SelectMany():

var qAll = items.SelectMany(item => new object[] { item.A, item.B });