I restored AdventureWorks2014 database from SQL Server 2014 to SQL Server 2017.
(I restored it twice, I changed the name on the 2nd restore, of course)
It works fine.
Now I tried to change the second database's compatibility to 140.
Now I want to test if I really change its compatibility by trying a function that is only available in SQL Server 2017.
SELECT CONCAT_WS(',','Count numers', 'one', 'two', 'three', 'four' ) AS counter;
The problem is, when I tried to ran it on the first database (which was still in compatibility 120), the script also worked. I looked at its compatibility but it still SQL Server 2014.
Is there something that I missed? Like SQL Server 2017 does something to older version databases that being restored to them that made the new function work in 2014 version databases?