In this article I will explain with an example, how to save file as binary data inside SQL Server database table and retrieve them and convert them back to their respective formats in ASP.Net using C# and VB.Net.
Database
This article makes use of a table named tblFiles whose schema is defined as follows.
![Save and Retrieve Files from SQL Server Database in ASP.Net using C# and VB.Net]()
Note: You can download the database table SQL by clicking the download link below.
Download SQL file
HTML Markup
The HTML Markup consists of:
FileUpload – For uploading file.
Button – For saving File in database.
The Button has been assigned with an OnClick event handler.
GridView –
GridView consists of a BoundField column and a TemplateField column.
BoundField – For displaying the Name of the File.
TemplateField – For displaying Download LinkButton.
<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="Upload" />
<hr />
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="Name" HeaderText="File Name"/>
<asp:TemplateField ItemStyle-HorizontalAlign = "Center">
<ItemTemplate>
<asp:LinkButton ID="lnkDownload" runat="server" Text="Download" OnClick="DownloadFile"
CommandArgument='<%# Eval("Id") %>'></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Namespaces
You will need to import the following namespaces.
C#
using System.IO;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
VB.Net
Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Uploading the Files in SQL Server Database table
When Upload button is clicked, following event handler is executed and the name of the uploaded File is fetched using the GetFileName function of the Path class.
And them the ContentType (MIME type) of the File is fetched from ContentType property of the FileUpload control.
Note: The Content type (MIME type) is very important while downloading the files as it notifies the browser about type of the File.
The file is read from the FileUpload control using InputStream property and converted into Byte Array (Binary Data) using the ReadBytes method of the BinaryReader class.
Finally, the Byte Array (Binary Data) will be inserted into Database using ADO.Net and the page is redirected to itself.
C#
protected void Upload(object sender, EventArgs e)
{
string filename = Path.GetFileName(FileUpload1.PostedFile.FileName);
string contentType = FileUpload1.PostedFile.ContentType;
using (Stream fs = FileUpload1.PostedFile.InputStream)
{
using (BinaryReader br = new BinaryReader(fs))
{
byte[] bytes = br.ReadBytes((Int32)fs.Length);
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
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", bytes);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
}
Response.Redirect(Request.Url.AbsoluteUri);
}
VB.Net
Protected Sub Upload(sender As Object, e As EventArgs)
Dim filename As String = Path.GetFileName(FileUpload1.PostedFile.FileName)
Dim contentType As String = FileUpload1.PostedFile.ContentType
Using fs As Stream = FileUpload1.PostedFile.InputStream
Using br As New BinaryReader(fs)
Dim bytes As Byte() = br.ReadBytes(DirectCast(fs.Length, Long))
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As New SqlConnection(constr)
Dim query As String = "INSERT INTO tblFiles VALUES (@Name, @ContentType, @Data)"
Using cmd As New SqlCommand(query)
cmd.Connection = con
cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = filename
cmd.Parameters.Add("@ContentType", SqlDbType.VarChar).Value = contentType
cmd.Parameters.Add("@Data", SqlDbType.Binary).Value = bytes
con.Open()
cmd.ExecuteNonQuery()
con.Close()
End Using
End Using
End Using
End Using
Response.Redirect(Request.Url.AbsoluteUri)
End Sub
Retrieving the uploaded files from Database Table in ASP.Net GridView
Inside the Page Load event, the BindGrid method is called and the GridView is populated with the records i.e. Files from the SQL Server Database Table.
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
this.BindGrid();
}
}
private void BindGrid()
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "SELECT Id, Name FROM tblFiles";
cmd.Connection = con;
con.Open();
GridView1.DataSource = cmd.ExecuteReader();
GridView1.DataBind();
con.Close();
}
}
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
Me.BindGrid()
End If
End Sub
Private Sub BindGrid()
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As New SqlConnection(constr)
Using cmd As New SqlCommand()
cmd.CommandText = "SELECT Id, Name FROM tblFiles"
cmd.Connection = con
con.Open()
GridView1.DataSource = cmd.ExecuteReader()
GridView1.DataBind()
con.Close()
End Using
End Using
End Sub
Downloading File from Database Table
When the Download LinkButton is clicked, first the File ID of the file to be downloaded is fetched using the CommandArgument property of the LinkButton.
The details of the File such as Name, Content Type and the File in Byte Array are fetched from the database using SqlDataReader.
Then, the Response class properties are set.
Properties:
1. ContentType – It informs the Browser about the file type. In this case it is PDF.
2. Content-Disposition – It is a response header indicating, the download file is an attachment and allows setting the file name.
Finally, using the BinaryWrite method of the Response class inside which Byte Array is passed as parameter, the File is written to the Response Stream using its Path and File is downloaded.
C#
protected void DownloadFile(object sender, EventArgs e)
{
int id = int.Parse((sender as LinkButton).CommandArgument);
byte[] bytes;
string fileName, contentType;
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
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", id);
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();
}
}
Response.Clear();
Response.Buffer = true;
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = contentType;
Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}
VB.Net
Protected Sub DownloadFile(sender As Object, e As EventArgs)
Dim id As Integer = Integer.Parse(TryCast(sender, LinkButton).CommandArgument)
Dim bytes As Byte()
Dim fileName As String, contentType As String
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As New SqlConnection(constr)
Using cmd As New SqlCommand()
cmd.CommandText = "SELECT Name, Data, ContentType FROM tblFiles WHERE Id=@Id"
cmd.Parameters.AddWithValue("@Id", id)
cmd.Connection = con
con.Open()
Using sdr As SqlDataReader = cmd.ExecuteReader()
sdr.Read()
bytes = DirectCast(sdr("Data"), Byte())
contentType = sdr("ContentType").ToString()
fileName = sdr("Name").ToString()
End Using
con.Close()
End Using
End Using
Response.Clear()
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = contentType
Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName)
Response.BinaryWrite(bytes)
Response.Flush()
Response.End()
End Sub
Screenshot
![Save and Retrieve Files from SQL Server Database in ASP.Net using C# and VB.Net]()
Downloads
