Oracle 电子邮件消息utl_mail.send中的sql语句

我正在发送电子邮件真正的甲骨文顶点，工作良好。然而，我需要的是在电子邮件的消息中有一个sql计数语句

我所拥有的是

begin
   utl_mail.send(sender     => 'a@test.com',
                  recipients =>'a@test.com',
                  subject    => 'FileRequest',
                  message    =>  'select count(filenumber) where status is assigned' files from registry '||:p5_filenumber ||''||'  ' ||:p5_filename || ' has now been assigned to the ' || :p5_department || '');

end;

这显然不起作用

我想看到的是

begin
   utl_mail.send(sender     => 'a@test.com',
                  recipients =>'a@test.com',
                  subject    => 'FileRequest',
                  message    =>  5 files from registry '||:p5_filenumber ||''||'  ' ||:p5_filename || ' has now been assigned to the ' || :p5_department || '');

end;

---

在发送邮件之前计算该值。大概是这样的：

declare
  l_cnt number;
  l_msg varchar2(200);
begin
  -- select number you're interested in
  select count(*)
    into l_cnt
    from some_table
    where some_conditions;

  -- compose the message
  l_msg := l_cnt ||' files from registry ...';

  -- send mail
  utl_mail.send(sender     => 'a@test.com',
                recipients => 'a@test.com',
                subject    => 'FileRequest',
                message    =>  l_msg);
end;