In this article I will explain with an example, how to save file as Binary data inside SQL Server database and also how to retrieve them reconvert 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 using ASP.Net
 
Note: You can download the database table SQL by clicking the download link below.
          Download SQL file
 
 

HTML Markup
The HTML Markup contains a FileUpload and Button to upload and save the files to database and an ASP.Net GridView control to display the uploaded files and also to allow the user to download the file saved in database. The ID of the File is bound to the CommandArgument property of the LinkButton. It will later be used to download the file.
<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="Upload" />
<hr />
<asp:GridView ID="GridView1" runat="server" HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White"
    RowStyle-BackColor="#A1DCF2" AlternatingRowStyle-BackColor="White" AlternatingRowStyle-ForeColor="#000"
    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 and then saving in SQL Server Database table
The below event handler gets executed when the Upload Button is clicked, it simply saves the file as Binary data in the SQL Server Database.
The name of the file, the content type (MIME type) and the actual file as array of bytes are inserted into the database table.
Note: The Content type (MIME type) is very important while downloading the files as it notifies the browser about type of the File.
 
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
 
 
Displaying the uploaded files from Database Table in ASP.Net GridView
Below is the code which populates the ASP.Net GridView from files saved in the database table.
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        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 IsPostBack Then
        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 particular file from Database Table using the Download Button in GridView
The below event handler is raised when the Download LinkButton is clicked inside the GridView Row. Firstly the ID of the File is determined using the CommandArgument property of the LinkButton and then the File data, i.e. Name, Content Type and the Byte Array is fetched from the database.
Once the data fetching process is completed the file is sent to the browser for downloading using the Response Stream.
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 using ASP.Net
 
 
Downloads