Define custom in-line comment designator

In MySQL, we can use # to designate that anything following it should be treated as an in-line comment.  It should be treated the same as if we were using -- before our in-line comment.

I think it would be great to be able to designate our own custom in-line or block comment indicator.

# this is a comment
SELECT 
    a.name # this is also a comment
    ,a.number -- this is also a comment
FROM db.table a;