In this article I will explain with an example, how to upload files, save (insert) file to Database Table, retrieve (display) files in HTML Grid and download the files from Database Table in ASP.Net Core Razor Pages.
Database
This article makes use of a table named tblFiles whose schema is defined as follows.
![ASP.Net Core Razor Pages: Upload Files, Save (Insert) file to Database and Download Files]()
Note: You can download the database table SQL by clicking the download link below.
Namespaces
You will need to import the following namespaces.
using System.IO;
using System.Data.SqlClient;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
Model
The following Model class consists of the following properties needed for inserting and populating the records of the Files from database.
public class FileModel
{
public int Id { get; set; }
public string Name { get; set; }
public string ContentType { get; set; }
public byte[] Data { get; set; }
}
Razor PageModel (Code-Behind)
The PageModel consists of the following three Handler methods.
Handler method for handling GET operation
Inside this Handler method, the GetFiles method is called and the public property Files is set.
Inside the GetFiles method, the records from the tblFiles table are fetched using DataReader and generic list of FileModel class objects is populated.
Finally, the generic list of FileModel public property is returned to the Razor Page.
Handler method for handling POST operation for uploading Files
This Handler method gets called when a File is selected and the Upload Button is clicked, and it gets the uploaded file in the IFormFile parameter.
The uploaded file is converted to an Array of Bytes using MemoryStream class and finally, is inserted into the database table.
After successful insert of the File, RedirectToPage is called which redirects to the IndexModel Get Handler method.
Handler method for handling File Download operation
When the Download Link inside the HTML Table (Grid) is clicked, then the ID of the particular file is sent to this Handler method and using the File ID, the File’s binary data is fetched from the database.
Finally, the File is downloaded using the File function.
public class IndexModel : PageModel
{
public List<FileModel> Files { get; set; }
private IConfiguration Configuration;
public IndexModel(IConfiguration _configuration)
{
Configuration = _configuration;
}
public void OnGet()
{
this.Files = this.GetFiles();
}
public IActionResult OnPostUploadFile(IFormFile postedFile)
{
string fileName = Path.GetFileName(postedFile.FileName);
string contentType = postedFile.ContentType;
using (MemoryStream ms = new MemoryStream())
{
postedFile.CopyTo(ms);
string constr = this.Configuration.GetConnectionString("MyConn");
using (SqlConnection con = new SqlConnection(constr))
{
string query = "INSERT INTO tblFiles VALUES (@Name, @ContentType, @Data)";
using (SqlCommand cmd = new SqlCommand(query))
{
cmd.Connection = con;
cmd.Parameters.AddWithValue("@Name", fileName);
cmd.Parameters.AddWithValue("@ContentType", contentType);
cmd.Parameters.AddWithValue("@Data", ms.ToArray());
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
return RedirectToPage("Index");
}
public FileResult OnGetDownloadFile(int fileId)
{
byte[] bytes;
string fileName, contentType;
string constr = this.Configuration.GetConnectionString("MyConn");
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "SELECT Name, Data, ContentType FROM tblFiles WHERE Id=@Id";
cmd.Parameters.AddWithValue("@Id", fileId);
cmd.Connection = con;
con.Open();
using (SqlDataReader sdr = cmd.ExecuteReader())
{
sdr.Read();
bytes = (byte[])sdr["Data"];
contentType = sdr["ContentType"].ToString();
fileName = sdr["Name"].ToString();
}
con.Close();
}
}
return File(bytes, contentType, fileName);
}
private List<FileModel> GetFiles()
{
List<FileModel> files = new List<FileModel>();
string constr = this.Configuration.GetConnectionString("MyConn");
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("SELECT Id, Name FROM tblFiles"))
{
cmd.Connection = con;
con.Open();
using (SqlDataReader sdr = cmd.ExecuteReader())
{
while (sdr.Read())
{
files.Add(new FileModel
{
Id = Convert.ToInt32(sdr["Id"]),
Name = sdr["Name"].ToString()
});
}
}
con.Close();
}
}
return files;
}
}
Razor Page (HTML)
Razor HTML Page consists of an HTML Form. The Form consists of an HTML FileUpload and a Submit Button.
Uploading the File
The Submit Button has been set with the POST Handler method using the asp-page-handler attribute.
Note: In the Razor PageModel, the Handler method name is OnPostUploadFile but here it will be specified as UploadFile when calling from the Razor HTML Page.
When the Submit Button is clicked, the UploadFile Handler method for handling POST operation will be called.
Downloading the File
The HTML Table contains an HTML Anchor Link for downloading the File.
The URL of the Anchor Link is set using the @Url.Page method which accepts the following three parameters:
1. Name of the PageModel class.
2. Name of the Handler method.
3. The name and the value of the Parameters to be passed to the Handler method.
When any Download Link is clicked, the DownloadFile Handler method is called and the File is downloaded.
Note: In the Razor PageModel, the Handler method name is OnGetDownloadFile but here it will be specified as DownloadFile when calling from the Razor HTML Page.
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.
@page
@addTagHelper*, Microsoft.AspNetCore.Mvc.TagHelpers
@model Upload_File_Database_Razor_Core.Pages.IndexModel
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
<style type="text/css">
body { font-family: Arial; font-size: 10pt; }
table { border: 1px solid #ccc; border-collapse: collapse; background-color: #fff; }
table th { background-color: #B8DBFD; color: #333; font-weight: bold; }
table th, table td { padding: 5px; border: 1px solid #ccc; }
table, table table td { border: 0px solid #ccc; }
</style>
</head>
<body>
<form method="post" enctype="multipart/form-data">
<input type="file" name="postedFile" />
<input type="submit" id="btnUpload" value="Upload" asp-page-handler="UploadFile" />
</form>
<hr/>
<table id="tblFiles" 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>
@foreach (var file in Model.Files)
{
<tr>
<td>@file.Id</td>
<td>@file.Name</td>
<td><a href="@Url.Page("Index", "DownloadFile", new { fileId = file.Id })">Download</a></td>
</tr>
}
</table>
</body>
</html>
Screenshot
![ASP.Net Core Razor Pages: Upload Files, Save (Insert) file to Database and Download Files]()
Downloads
