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

array_merge will not work with any iterable

The Mysql family does not seem to like that one.

The docs only talk about 2008 and up, not sure if those should be added
to 2005 too.

It was possible to provide escaping through the second argument but that
was more like a hack.

Inherit table charset/collation from db charset

[CS] A cast statement must be followed by a single space

Use @var instead of @param

removed an else condition, fixed a parameter annotation and make little improvements

Forward compatibility with 3.x

Expressed PARAM_*_ARRAY through other constants to eliminate the dependency on the actual constant values

Close #2998
the commit.