We able to use HAVING clause in SQL-query to filtrate groups of row. When we use GROUP BY clause it work directly in this way.
But, let's look to this query:
select 1 where 1!=1 having count(*)=0;
If there's no
GROUP BY an aggregate always returns a row, in your case the
This column is not in your Select list, but the hard-coded literal
select count(*) where 1!=1 ; select 'bla' where 1!=1 having count(*)=0;