For testing purposes and not only, it may be needed to evaluate an arbitrary SQL expression (see https://github.com/doctrine/dbal/pull/3013, https://github.com/doctrine/dbal/pull/3108). Instead of doing `str_replace()` on an expected string, one could specify the expression explicitly.

This should take care of most idiosyncracies.

See
https://stackoverflow.com/questions/1881853/select-without-a-from-clause-in-oracle

The Mysql family does not seem to like that one.