I am surprised that the parameter is even being handled
properly . I would expect it to expand to something along the lines of: ... in ("1,2,3,4,5,6"). In the past, I have done something like splitting the string into an array, building the parameter list using the x (repetition) operator ("... in (" . join(",", ("?")x$size) . ")..."), and then passing the array to execute. I also think that DBIx::PreQL handles an arrayref properly for building this type of query.