c# 如何实现保存文件到数据库

//从form 中获取fileData

HttpFileCollection files = Request.Files;
byte[] fileData = new byte[files[0].ContentLength];
files[0].InputStream.Read(fileData, 0, fileData.Length);

void FileStateHandle(string connstr, OptType opt, string fileName,byte[] fileData, string state, string message)
        {
            SqlConnection sqlconn;
            string commandText = null;
            SqlCommand cmd = new SqlCommand();

            message = message.Replace("'", "''");
            fileName = fileName.Replace("'", "''");
            sqlconn = new SqlConnection(connstr);
            switch(opt){
                case OptType.Insert:
                    commandText = "insert into dbo.SalesTraceUploadedFiles(FileName,FileData,State,Message,Date) select "
                        + "'" + fileName + "'"
                        + ", @fileData"
                        + ",'" + state
                        + "','" + message
                        + "',getdate()";
                    cmd.CommandText = commandText;
　　　　　　　//此处是重点哦 将filedata 赋值进去
                    SqlParameter prmFileData = new SqlParameter("@fileData", SqlDbType.VarBinary);
                    prmFileData.Value = fileData;
                    prmFileData.Size = fileData.Length;
                    cmd.Parameters.Add(prmFileData);
                    break;
                case OptType.Update:
                    commandText = "update SalesTraceUploadedFiles set Message = '"+message+"' ,State = '" + state
                        + "' where FileName = '" + fileName + "'";
                    cmd.CommandText = commandText;
                    break;           
            }          
           
            try
            {
                cmd.Connection = sqlconn;
                sqlconn.Open();
                cmd.ExecuteNonQuery();
            }
            catch
            {
                throw;
            }
            finally{
                sqlconn.Close();
                cmd.Dispose();
            }
        }