|
| Intro | | Uploading images to a Sql Server database is extremely easy using ASP.NET and C#. A couple of months ago I wrote a similar article, using VB.NET. This article will show you how to upload Images (or any Binary Data ) to a Sql Server database using ASP.NET and C#. Part II, Retrieving Images from a Database ( C# ) , will show you how extract images from a database. | | | | Building the Database Table | | We start out by building our database table. Our image table is going to have a few columns describing the image data, plus the image itself. Here is the sql required to build our table in SQL Server or MSDE. | CREATE TABLE [dbo].[image] (
[img_pk] [int] IDENTITY (1, 1) NOT NULL ,
[img_name] [varchar] (50) NULL ,
[img_data] [image] NULL ,
[img_contenttype] [varchar] (50) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
ALTER TABLE [dbo].[image] WITH NOCHECK ADD
CONSTRAINT [PK_image] PRIMARY KEY NONCLUSTERED
(
[img_pk]
) ON [PRIMARY] GO | | I'm a great fan of having a single column primary key, and making that key an Identity column, in our example, that column is img_pk. The next column is img_name, which is used to store a friendly name of our image, for example "Mom and Apple Pie". img_data is actually our image data column, and is where we will be storing our binary image data. img_contenttype will be used to record the content-type of the image, for example "image/gif" or "image/jpeg" so we will know what content-type we need to output back to the client, in our case the browser. | | | | Building our Webform | | Now that we have a warm, fuzzy place to store our images, lets build a webform to upload our images into the database. | Enter A Friendly Name<input type=text id=txtImgName runat="server" >
<asp:RequiredFieldValidator id=RequiredFieldValidator1 runat="server" ErrorMessage="Required" ControlToValidate="txtImgName"></asp:RequiredFieldValidator>
<br>Select File To Upload:
<input id="UploadFile" type=file runat=server>
<asp:button id=UploadBtn Text="Upload Me!" OnClick="UploadBtn_Click" runat="server"></asp:button>
</form> | | The first interesting point about our webform, is the attribute "enctype". Enctype tells the browser and server that we will be uploading some type of binary data. This binary data needs to be parsed, using a different mechanism from our normal text data. The next control we of interest is the type=file control. This control will present the user with an upload file dialog box. The user browses for the file they want to upload. | | | | Working with the Uploaded Image | | Once the user posts the data, we have to be able to parse the binary data and send it to the database. Along with the main body of the code, we use a helper function called SaveToDB() to achieve this. | private int SaveToDB(string imgName, byte[] imgbin, string imgcontenttype)
{
//use the web.config to store the connection string
SqlConnection connection = new SqlConnection(ConfigurationSettings.AppSettings["DSN"]);
SqlCommand command = new SqlCommand( "INSERT INTO Image (img_name,img_data,img_contenttype) VALUES ( @img_name, @img_data,@img_contenttype )", connection );
SqlParameter param0 = new SqlParameter( "@img_name", SqlDbType.VarChar,50 );
param0.Value = imgName;
command.Parameters.Add( param0 );
SqlParameter param1 = new SqlParameter( "@img_data", SqlDbType.Image );
param1.Value = imgbin;
command.Parameters.Add( param1 );
SqlParameter param2 = new SqlParameter( "@img_contenttype", SqlDbType.VarChar,50 );
param2.Value = imgcontenttype;
command.Parameters.Add( param2 );
connection.Open();
int numRowsAffected = command.ExecuteNonQuery();
connection.Close();
return numRowsAffected;
}
| In this function we are passing in 3 different parameters
imgName - the friendly name we want to give out image data
imgbin -- the binary or Byte array of our data
imgcontenttype - the content type of our image. For example: image/gif or image/jpeg
There are 3 parameters as SQLParameters and defines the type. Our first SQLParameter is @img_name and is defined as a VarChar with a length of 50. The 2nd parameter, @img_data, is the binary or Byte() of data and is defined with a data type of Image. The last parameter is @img_contenttype, is defined as a VarChar with a length of 50 characters. The remainder of the function opens a connection to the database and executes the command by calling command.ExecuteNonQuery(). | | | | Calling our Functions | | Ok, now that we have our worker functions written, let's go ahead and get our image data. | Stream imgStream = UploadFile.PostedFile.InputStream;
int imgLen = UploadFile.PostedFile.ContentLength;
string imgContentType = UploadFile.PostedFile.ContentType;
string imgName = txtImgName.Value;
byte[] imgBinaryData = new byte[imgLen]; | We need to access three important pieces of data for our example. We need the image:
Name (imgName_value)
Content-Type (imgContentType)
and the Image Data. (imgBindaryData)
First we access to the image stream, which we are able to get by using the property UploadFile.PostedFile.InputStream. (Remember, UploadFile was the name of our upload control on the webform). We also need to know how long the Byte array we are going to create needs to be. We can get this number by calling UploadFile.PostedFile.ContentLength, and storing it's value in imgLen. Once we have the length of the image, we create a byte array by byte[] imgBinaryData = new byte[imgLen]; We access the content type of the image by accessing the ContentType property of UploadFile.PostedFile. Lastly we need the friendly name we are going to use for the image. | | | | The Good Stuff | | Ok, we know how to connect to the database, we know how to insert data into the database, and we have access to the uploaded image's properties. But how do we pass the stream of the image to SaveToDB(). Again, .NET comes to the rescue. With 1 line of code we are able to access the image stream and convert it to a Byte array. | | int n = imgStream.Read(imgBinaryData,0,imgLen); | The stream object provides a method called Read(). Read() takes 3 parameters:
buffer - An array of bytes. A maximum of count bytes are read from the current stream and stored in buffer.
offset -The byte offset in buffer at which to begin storing the data read from the current stream.
count - The maximum number of bytes to be read from the current stream.
So we pass in our Byte array, imgBinaryData; the place to start at, 0; and the amount of bytes we want to read. n number of bytes read into our array is returned. | | | | Extending Beyond Images | | Because we are able to access the binary stream of data, images are not the only object we can store in the database. Some other objects might be streaming video, com objects, or sound clips. As an example I also uploaded a streaming avi into my database. I ran a select query to show the results. | | | | | Conclusion | | So there we have it, ASP.NET provides us some easy functionality for uploading images into a database. In Part II, we will actually look at pulling these images out of a database and sending them to a browser. The complete code used for this article can be found below. | | | Cheers!
Dave
www.123aspx.com | | | | Image SQL | CREATE TABLE [dbo].[image] (
[img_pk] [int] IDENTITY (1, 1) NOT NULL ,
[img_name] [varchar] (50) NULL ,
[img_data] [image] NULL ,
[img_contenttype] [varchar] (50) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
ALTER TABLE [dbo].[image] WITH NOCHECK ADD
CONSTRAINT [PK_image] PRIMARY KEY NONCLUSTERED
(
[img_pk]
) ON [PRIMARY]
GO | | | | UploadImage.aspx | <%@ Page language="c#" Src="UploadImage.aspx.cs" Inherits="DBImages.UploadImage" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
</HEAD>
<body bgcolor=#ffffff>
<form enctype="multipart/form-data" runat=server id=form1 name=form1>
<h3>The ASPFree Friendly Image Uploader</h3>
Enter A Friendly Name<input type=text id=txtImgName runat="server" >
<asp:RequiredFieldValidator id=RequiredFieldValidator1 runat="server" ErrorMessage="Required" ControlToValidate="txtImgName"></asp:RequiredFieldValidator>
<br>Select File To Upload:
<input id="UploadFile" type=file runat=server>
<asp:button id=UploadBtn Text="Upload Me!" OnClick="UploadBtn_Click" runat="server"></asp:button>
</form>
</body>
</HTML> | | | | UploadImage.aspx.cs ( codebehind file) | using System;
using System.Configuration;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.IO;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace DBImages
{
public class UploadImage : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Button UploadBtn;
protected System.Web.UI.WebControls.RequiredFieldValidator RequiredFieldValidator1;
protected System.Web.UI.HtmlControls.HtmlInputText txtImgName;
protected System.Web.UI.HtmlControls.HtmlInputFile UploadFile;
public UploadImage() { }
private void Page_Load(object sender, System.EventArgs e){ }
public void UploadBtn_Click(object sender, System.EventArgs e)
{
if (Page.IsValid) //save the image
{
Stream imgStream = UploadFile.PostedFile.InputStream;
int imgLen = UploadFile.PostedFile.ContentLength;
string imgContentType = UploadFile.PostedFile.ContentType;
string imgName = txtImgName.Value;
byte[] imgBinaryData = new byte[imgLen];
int n = imgStream.Read(imgBinaryData,0,imgLen);
int RowsAffected = SaveToDB( imgName, imgBinaryData,imgContentType);
if ( RowsAffected>0 )
{
Response.Write("<BR>The Image was saved");
}
else
{
Response.Write("<BR>An error occurred uploading the image");
}
}
}
private int SaveToDB(string imgName, byte[] imgbin, string imgcontenttype)
{
//use the web.config to store the connection string
SqlConnection connection = new SqlConnection(ConfigurationSettings.AppSettings["DSN"]);
SqlCommand command = new SqlCommand( "INSERT INTO Image (img_name,img_data,img_contenttype) VALUES ( @img_name, @img_data,@img_contenttype )", connection );
SqlParameter param0 = new SqlParameter( "@img_name", SqlDbType.VarChar,50 );
param0.Value = imgName;
command.Parameters.Add( param0 );
SqlParameter param1 = new SqlParameter( "@img_data", SqlDbType.Image );
param1.Value = imgbin;
command.Parameters.Add( param1 );
SqlParameter param2 = new SqlParameter( "@img_contenttype", SqlDbType.VarChar,50 );
param2.Value = imgcontenttype;
command.Parameters.Add( param2 );
connection.Open();
int numRowsAffected = command.ExecuteNonQuery();
connection.Close();
return numRowsAffected;
}
}
}
| | | | Web.Config | <configuration>
<appSettings>
<add key="DSN" value="server=localhost;uid=sa;pwd=;Database=aspfree"/>
</appSettings>
<system.web>
<customErrors mode="Off" />
</system.web>
</configuration> | | | | | | | | |
|
| DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware. |
More ASP.NET Articles
More By aspfree  developerWorks - FREE Tools!
|
This whitepaper presents the benefits of successfully introducing static analysis into your organization using IBM Rational Software Analyzer. Additionally, it identifies some common pitfalls that can hinder the effective use of static analysis tooling as well as presents 10 simple strategies designed to help you quickly realize the value of static analysis using Rational Software Analyzer.
FREE! Go There Now!
| | | |
CakePHP is a stable production-ready, rapid-development aid for building Web sites in PHP. This "Cook up Web sites fast with CakePHP" series shows you how to build an online product catalog using CakePHP.
FREE! Go There Now!
| | | |
Visit IBM developerWorks to download a free trial version of WebSphere Business Modeler Advanced V6.1.1, IBM’s premier business process modeling and analysis tool for business users that offers process modeling, simulation, and analysis capabilities. IBM WebSphere Business Modeler helps you visualize, understand, and document business processes for continuous improvement.
FREE! Go There Now!
| | | |
Download a free trial version of IBM Rational Software Analyzer Developer Edition V7.0 to identify bug defects earlier in the software development cycle. Rational Software Analyzer is an extensible software development solution that reduces the expense of bug-fixes by enabling static analysis code reviews and bug identification very early in the development cycle.
FREE! Go There Now!
| | | |
Secure your Web applications with IBM Rational AppScan Standard Edition V7.7, previously known as Watchfire AppScan. This Web application security testing tool automates vulnerability assessments and scans and tests for common Web application vulnerabilities. Visit IBM developerWorks to download a free trial of IBM Rational AppScan Standard Edition V7.7.
FREE! Go There Now!
| | | |
Learn how Rational Build Forge can extend a simple compile and package build process by adding customization and deployment capability. Go from a manual method to automating: checking for code changes; getting the latest source; compiling and packaging; customizing; copying to and restarting a deployment server; and sending e-mail notification that a new version is available.
FREE! Go There Now!
| | | |
Visit IBM developerWorks to try the IBM SOA Sandbox for people. The SOA Sandbox for people provides a trial environment with the necessary tooling and components required to enable consistent human and process interaction and collaboration, showing how you can improve user experience and business productivity.
FREE! Go There Now!
| | | |
The Eclipse community is constantly working to extend Eclipse's functionality. In this webcast, learn about some of the most important and feature-rich projects under development. From multi-language support to plug-in development, tune in to see what Eclipse is capable of now.
FREE! Go There Now!
| | | |
Join this webcast to learn how IBM Rational's Functional Testing solution enables you to implement automation your way, at your pace, with your existing staff. In this webcast, you’ll learn how you can eliminate redundancy of manual test scripts, reduce errors, and increase test coverage through test automation. After this presentation you will understand how IBM Rational Functional Testing solution can streamline your manual testing and make test automation easily attainable.
FREE! Go There Now!
| | | |
WebSphere Process Server delivers a unique integration framework that simplifies existing IT resources. Often, as IT assets grow to support business demand, so too does their complexity and manageability. In this webcast, we’ll discuss how WebSphere Process Server helps deliver an SOA infrastructure that provides a common model to orchestrate, mediate, connect, map, and execute the underlying IT functions. Discover how WebSphere Process Server simplifies integration of business processes by leveraging existing IT assets as reusable services without the complexities of traditional integration methodologies.
FREE! Go There Now!
| | | |
All FREE IBM® developerWorks Tools!
| |
