[do_jdbc] Begin adding special behaviour for pgsql queries using RETURNING
[do_jdbc] Begin adding special behaviour for pgsql queries using RETURNING

* RETURNING queries should use PreparedStatement.executeQuery()
  and not executeUpdate(), and the ResultSet returned should be
  handled appropriately.

Signed-off-by: Alex Coles <07b1bd43bec0751d878a3f03ea589427ab84a876@mac.com>

simonkro/do_mysql,simonkro/do_mysql,simonkro/do_mysql