PL/SQL :: Test Data In Query?

I suspect it uses TABLE, CAST and/or MULTISET functions in a query .. but reading the docs on those, I can't seem to piece together how to do it.

When I piece together a sample/test query, I usually do something like this:

WITH data AS
( SELECT 123  id,  'abc'  col1  FROM dual UNION ALL
SELECT 234, 'def' FROM dual UNION ALL
SELECT 345, 'xyz' FROM dual
)
SELECT *
FROM data -- usually more complex query here

However, I saw somebody do this without using the UNION ALL .. they did something with TABLE ( ... ) ? it seemed "simpler" than the UNION ALL method I've used previously