请问为什么我上传图片以二进制流的方式保存到数据库时候报错呢？新增一个公告信息时发生错误，错误信息：将截断字符串或二进制数据。

下面是源码：
 SqlParameter[] para = { new SqlParameter("@PID", privateAch.PID),
                                              new SqlParameter("@ID", privateAch.ID),
                                              new SqlParameter("@PersonID", privateAch.PersonID),
                                              new SqlParameter("@AchName", privateAch.AchName),
                                              new SqlParameter("@AchAddress", privateAch.AchAddress),
                                              new SqlParameter("@CreateTime",privateAch.CreateTime),
                                              new SqlParameter("@IsDelete",privateAch.IsDelete),
                                              new SqlParameter("@Type",privateAch.Type),
                                              new SqlParameter("@Bsmall",privateAch.Bsmall),
                                              new SqlParameter("@WJL",privateAch.WJL)};
                    string sql = "IF EXISTS(SELECT * FROM T_PrivateAch WHERE ID=@ID) begin update  T_PrivateAch set PID=@PID,PersonID=@PersonID,AchName=@AchName,AchAddress=@AchAddress,CreateTime=@CreateTime,IsDelete=@IsDelete,Type=@Type,Bsmall=@Bsmall,WJL=@WJL where ID=@ID end else begin insert into T_PrivateAch(ID,PID,PersonID,AchName,AchAddress,CreateTime,IsDelete,Type,Bsmall,WJL) values(@ID,@PID,@PersonID,@AchName,@AchAddress,@CreateTime,@IsDelete,@Type,@Bsmall,@WJL); end";
                    return OperatorProxy.Add("新增一个公告信息", sql, para);
这个是我的二进制流
类型为：/// <summary>
/// 文件流
 /// </summary>
        public  byte [] WJL
        {
            get { return _wjl; }
            set { _wjl = value; }
        } 对其进行赋值：byte[] fileByte = null;
fileByte = ConvertFileToBytes(file);
privateAch.WJL = fileByte;    public byte[] ConvertFileToBytes(HttpPostedFile oFile)
    {
        Stream sm = oFile.InputStream;
        byte[] bytes = new byte[oFile.ContentLength];
        sm.Read(bytes, 0, oFile.ContentLength);        return bytes;
    }