救命！！SqlServer的Image类型与Oracle的Blob互相写入的问题

Question

这个星期必须搞定的....
SqlServer中S表有个字段是Image类型，用于存放Mail附件的
Oracle中O表也有个字段Blob类型，也是存放Mail附件的我要把一些sqlserver中的附件数据导入到oracle中，同时也有一些Oracle中的附件导入到sqlserver中。
但是无论是把sqlserver的数据写入oracle，还是把oracle的blob数据写入sqlserver，都会出错。
哪位高手帮帮忙看一下，感激不尽了...
如果可以的话小弟可以把剩下来的代码都发过去方便大大们诊断..其中邮件操作的那一段代码如下：        private void TransferMailing()
        {            string maildomain = textBoxMailDomain.Text;       
            string oaSql = "select * from rx_oa_mailing where Instr(MailTo,'" + maildomain + "')<1";
            DataSet ds = SqlHelper.ExecuteReader(this.OAConnction.ConnectionString, this.OAConnction.ProviderName, oaSql);            if (ds.Tables.Count > 0)
            {
                DataTable dt = ds.Tables[0];
                foreach (DataRow dr in dt.Rows)
                {
                    string mailId = dr["mail_Id"].ToString().Trim();
                    string mailTo = dr["mailto"].ToString().Trim();
                    string mailFrom = dr["mailer_addr"].ToString().Trim();
                    string fromName = dr["mailer_name"].ToString().Trim();
                    string copyTo = dr["copyTo"].ToString().Trim();
                    string privateTo = dr["privateTo"].ToString().Trim();
                    string subject = dr["subjet"].ToString().Trim();
                    string content = dr["content"].ToString().Trim().Replace("'","");
                    string attachSum = dr["attachsum"].ToString().Trim();                    if (mailTo.IndexOf("@" + maildomain) < 0)
                    {
                        string mailSql = "insert into OA_MAIL(MAILFROM,FROM_NAME,MAILTO,CCLIST,BCCLIST,SUBJECT,CONTENT,ATTACH_COUNT)";
                        mailSql += " values('" + mailFrom + "','" + fromName + "','" + mailTo + "','" + copyTo + "','" + privateTo + "','" + subject + "','" + content + "'," + attachSum + ") select @@identity";                        labelMailing.Text = "当前发送邮件至" + mailTo;                        DataSet mailds = new DataSet();                        //Send Mailing Attach
                        try
                        {
                            mailds = SqlHelper.ExecuteReader(this.MailConnction.ConnectionString, this.MailConnction.ProviderName, mailSql);
                        }
                        catch (Exception ce)
                        {
                            logger.Error("OA to Mail Body:" + ce.Message);
                        }                        if (mailds.Tables.Count > 0)
                        {
                            string newMailId = mailds.Tables[0].Rows[0][0].ToString().Trim();
                            //insert mailing Attach
                            string oaAttachSql = "select * from RX_OA_Mailing_Attach where Mail_Id=" + mailId;                            DataSet ads = SqlHelper.ExecuteReader(this.OAConnction.ConnectionString, this.OAConnction.ProviderName, oaAttachSql);                            if (ads.Tables.Count > 0)
                            {
                                DataTable adt = ads.Tables[0];                                foreach (DataRow adr in adt.Rows)
                                {
                                    string filename = adr["FileName"].ToString().Trim();
                                    byte[] filecontent = (Byte[])adr["Content"];                                    string mailAttachSql = "insert into OA_Attach(ID_NUM,FILENAME,CONTENT) values(@mailid,@filename,@filecontent)";                                    Hashtable ht = new Hashtable();
                                    ht.Add("mailid", newMailId);
                                    ht.Add("filename", filename);
                                    ht.Add("filecontent", filecontent);                                    try
                                    {
                                        SqlHelper.ExecuteQueryByParam(this.MailConnction.ConnectionString, this.MailConnction.ProviderName, mailAttachSql, ht);
                                    }　　
                                    catch(Exception ce)
                                    {
                                        logger.Error("OA to Mail Attach:" + ce.Message);
                                    }                                }
                            }                            //Delete mailing
                            string deleteMailSql = "delete from rx_oa_mailing where mail_Id=" + mailId;
                            SqlHelper.ExecuteNonQuery(this.OAConnction.ConnectionString, this.OAConnction.ProviderName, deleteMailSql);
                            
                        }                        labelMailing.Text = "发送邮件至" + mailTo + "完成";
                    }
                    else
                    {
                        string deleteMailSql = "delete from rx_oa_mailing where mail_Id=" + mailId;
                        SqlHelper.ExecuteNonQuery(this.OAConnction.ConnectionString, this.OAConnction.ProviderName, deleteMailSql);
                    }
                
                }
            
            }
        
        }