下载多个上传的文件

我将多个文件以字节的形式上传到数据库表中,现在如何以zip的形式下载文件?我的代码如下: 看法

@using (Html.BeginForm(Html.BeginForm("upload", "Home", FormMethod.Post, new { @id = "form", enctype = "multipart/form-data" })))
        {
            <input type="file" multiple="multiple" name="files" id="files" />
            <div class="form-group">
                <div class="col-md-offset-2 col-md-10">
                    <input type="submit" value="Submit" class="btn btn-default" />
                </div>
            </div>
        }

控制器:

    public FileContentResult GetFile(int id)
    {
        
        SqlDataReader rdr; byte[] fileContent = null;
        string mimeType = ""; string fileName = "";
        string constr = WebConfigurationManager.ConnectionStrings["DbContextModel"].ConnectionString;

        using (SqlConnection con = new SqlConnection(constr))
        {
            var qry = "SELECT * FROM myTable WHERE ID = @ID";
            var cmd = new SqlCommand(qry, con);
            cmd.Parameters.AddWithValue("@ID", id);
            con.Open();
            rdr = cmd.ExecuteReader();
            if (rdr.HasRows)
            {
                rdr.Read();
                fileContent = (byte[])rdr["Attachments"];

            }
        }
        return File(fileContent, "application/zip", "download.zip");
        
    }

模型

  public partial class myTable
 {
  public int id {get;set;}
  public byte[] Attachments { get; set; }
  }

无法打开download.zip文件。“压缩的压缩文件夹无效”。请告知。提前谢谢。

上传功能:

...
     byte[] bytes = new byte[] { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20 };
            MemoryStream target = new MemoryStream();
            foreach (var file in files)
            {
                if (file.ContentLength > 0)
                { 
                     file.InputStream.CopyTo(target);
                    bytes = target.ToArray();
               
                }
                
            }