Wow, nice. That will make some things much easier, however seeing that it it mostly supported then I think that fragment in from should be supported as well in near future.

Thanks! It works:

"foo"
|> with_cte("foo", as: fragment("""
SELECT * FROM (VALUES (1,2),(3,4)) AS foo (x,y)
"""))
|> select([foo], {foo.x, foo.y})
|> Repo.all()

[debug] QUERY OK source="foo" db=2.7ms queue=0.6ms idle=1721.4ms
WITH "foo" AS (SELECT * FROM (VALUES (1,2),(3,4)) AS foo (x,y)) SELECT f0."x", f0."y" FROM "foo" AS f0 []
[{1, 2}, {3, 4}]

Since Ecto 3.11.0 you can use values/2 as described here

values = [%{id: 1, text: "abc"}, %{id: 2, text: "xyz"}]
types = %{id: :integer, text: :string}

query =
  from v1 in values(values, types),
    join: v2 in values(values, types),
    on: v1.id == v2.id

Repo.all(query)