The only focus of this example is to upload and download files, so I did not pay any attention on OO design, Design Patterns, and coding standards. For simplicity, I did not even put exception handling in the code.
NET to access the database, but you can definitely use more advanced techniques such as Entity Framework , Hibernate , and Stored Procedures to take advantage of whatever advantages these techniques can provide you. NET for those interested. Although I did not test it myself since I do not have earlier versions myself, I feel that you can simply copy and paste the code in your application in earlier versions. In this article, I will first introduce how to create the SQL Server database for this application and then show you how to upload and download files in this ASP.
NET application. To create the database, you need to have "administrative" permissions in SQL Server. You can run the following script to create the database:.
The above script is "safe". But before you run it, please double check if your server accidentally already has a database named "AFileStorageDB". If so, the script will drop your database and create the new one and you may risk losing all your data. The database table "Files" created by the script is shown in the following picture:.
Here is a function that can be used to compare if the file submitted by the web user is among the list of valid extensions. Developers can use the same. NET code to compare the uploaded file's extension against a banned list of file extentions. If you examine the web. Look at the below section copied down here from the web. If we split the AllowedFileExtensions key value, we can get an array of the confirmed extensions.
Below is a similar way of keeping valid extensions hardcoded as an array in the application instead of using the web configuration file. If the file extension tests are successfull then we have two choice, one is saving the uploaded file in a file folder that can be reached from the web server, and also that has the write permission. Let's select the first one, save the file on a web folder. Saving the file to the web folder that is parameterized using the web. Let's continue now with the saving to database selection.
First create a SqlConnection object getting the connection string from the configuration file connection strings section. Then a SqlDataAdapter object is created from the Files database table using the following select sql statement. And the following codes creates a new row of the Files datatable in the dataset and sets its columns with the filename and the stream object as the binary file.
This page is used as a displayed list of files uploaded successfully into the sql server database. Here is the ASP. When the HyperLinkField column of the GridView object is clicked the id field value which is unique in the Files database table is passed as a querystring parameter to the file. After reading image file, File. Item "id" enables us to read the querystring parameters for the id parameter value of the uploaded file to SQL Server database. You can better keep the content type or the MIME type of the saved filed as a property of itself.
Because if the uploaded file is a. I hope ASP. NET Web Site link. End ;. Parse TryCast sender, LinkButton. Dim bytes As Byte. AddWithValue " Id" , id. BinaryWrite bytes. Related Articles. Add Comments. Thank you for the feedback. The comment is now awaiting moderation. You will be notified via email when the author replies to your comment. Please select a comment to reply.
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