In this article I will explain with an example, how to download (save) VARBINARY data from SQL Server database table using Entity Framework in ASP.Net MVC Razor.
Files will be uploaded and then will be saved (inserted) to database table as VARBINARY data. The file in VARBINARY data format will be retrieved and displayed in HTML Grid (Table) consisting of a Link for downloading the VARBINARY data as file from database.
Database
This article makes use of a table named tblFiles whose schema is defined as follows.
![ASP.Net MVC: Download (Save) VARBINARY Data as File]()
Note: You can download the database table SQL by clicking the download link below.
Entity Framework Model
Once the Entity Framework is configured and connected to the database table, the Model will look as shown below.
![ASP.Net MVC: Download (Save) VARBINARY Data as File]()
Namespaces
You will need to import the following namespace.
Controller
The Controller consists of three Action methods.
Action method for handling GET operation
Inside this Action method, all the files are fetched using Entity Framework and are returned to the View.
Action method for handling POST operation for uploading Files
This Action method gets called when a File is selected and the Upload Button is clicked, and it gets the uploaded file in the HttpPostedFileBase parameter.
The uploaded file is converted to an Array of Bytes using BinaryReader class and finally is inserted into the database table.
Action method for handling POST operation for downloading Files
When the Download Link inside the HTML Table (Grid) is clicked, then the ID of the particular file is sent to this Action method and using the File ID, the File’s binary data is fetched from the database using Entity Framework.
Note: The following Action method performs File Download and hence the return type is set to FileResult.
Finally the File is downloaded using the File function.
public class HomeController : Controller
{
// GET: Home
public ActionResult Index()
{
FilesEntities entities = new FilesEntities();
return View(entities.tblFiles.ToList());
}
[HttpPost]
public ActionResult Index(HttpPostedFileBase postedFile)
{
byte[] bytes;
using (BinaryReader br = new BinaryReader(postedFile.InputStream))
{
bytes = br.ReadBytes(postedFile.ContentLength);
}
FilesEntities entities = new FilesEntities();
entities.tblFiles.Add(new tblFile
{
Name = Path.GetFileName(postedFile.FileName),
ContentType = postedFile.ContentType,
Data = bytes
});
entities.SaveChanges();
return RedirectToAction("Index");
}
[HttpPost]
public FileResult DownloadFile(int? fileId)
{
FilesEntities entities = new FilesEntities();
tblFile file = entities.tblFiles.ToList().Find(p => p.id == fileId.Value);
return File(file.Data, file.ContentType, file.Name);
}
}
View
Inside the View, in the very first line the Entity Model class is declared as IEnumerable which specifies that it will be available as a Collection.
The View consists of two Forms:-
Form for Uploading the File
This Form consists of an HTML FileUpload and a Submit Button. When the Button is clicked, the Index Action method for handling POST operation will be called.
Form for Downloading the File
This Form consists of an HTML HiddenField and a Hidden Submit Button. When any Download Link inside the HTML Table (Grid) is clicked, then the DownloadFile JavaScript function is called, which sets the FileId into the HiddenField and calls the click event of the Submit button which submits the Form.
When the Form is submitted, the DownloadFile Action method is called, which performs the File download operation.
Displaying the Files
For displaying the files, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the File records.
@model IEnumerable<Save_Files_Database_EF_MVC.tblFile>
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width"/>
<title>Index</title>
</head>
<body>
@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="postedFile"/>
<input type="submit" id="btnUpload" value="Upload"/>
}
@using (Html.BeginForm("DownloadFile", "Home", FormMethod.Post))
{
<input type="hidden" id="hfFileId" name="FileId"/>
<input type="submit" id="btnDownload" value="Download" style="display:none"/>
}
<hr/>
<table cellpadding="0" cellspacing="0">
<tr>
<th style="width:50px">File ID</th>
<th style="width:120px">File Name</th>
<th style="width:80px">Download</th>
</tr>
@if (Model.Count() > 0)
{
foreach (var file in Model)
{
<tr>
<td>@file.id</td>
<td>@file.Name</td>
<td><a href="javascript:;" onclick="DownloadFile(@file.id)">Download</a></td>
</tr>
}
}
else
{
<tr>
<td colspan="3"> </td>
</tr>
}
</table>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
function DownloadFile(fileId) {
$("#hfFileId").val(fileId);
$("#btnDownload")[0].click();
};
</script>
</body>
</html>
Screenshot
![ASP.Net MVC: Download (Save) VARBINARY Data as File]()
Downloads
