/*
 * call-seq:
 *    res.oid_value() -> Fixnum
 *
 * Returns the +oid+ of the inserted row if applicable,
 * otherwise +nil+.
 */
static VALUE
pgresult_oid_value(VALUE self)
{
        Oid n = PQoidValue(get_pgresult(self));
        if (n == InvalidOid)
                return Qnil;
        else
                return INT2FIX(n);
}