web application generator

Amazon Simple Storage Service (Amazon S3) is a cloud-based data storage solution. Let’s add fields to the Suppliers table in the Northwind database in order to store company logos. The picture file name, size, and content type will be saved in the database, while the files will be uploaded to S3.

Setting Up S3

Navigate to http://aws.amazon.com/s3 and log in to your account. If you do not have an active account for Amazon S3, sign up for AWS Free Usage Tier.

When logged into the AWS Management Console, select S3 under Storage & Content Delivery section. Click on Create Bucket.

Enter a bucket name and press Create.

When complete, click on the account name in the top right corner and select Security Credentials. Scroll down to Access Keys section. If necessary, create a new access key. Click on Show under Secret Access Key and save both the Secret Access Key and Access Key ID for later use.

Adding Utility Fields to the Database

Start SQL Server Management Studio. In the Object Explorer, right-click on Databases / Northwind / Tables / dbo.Suppliers, and press Design.

Add the following columns:

Save the changes. Switch to the generator and click on the project name. Select Refresh, check the box next to Suppliers controller, and proceed to refresh the web app.

Configuring BLOB Field

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Suppliers / Fields node, and press New Field.

Assign the following properties:

Save the field. Drag the new field node and drop it onto Suppliers/ Views / editForm1 to instantiate the field as a data field in the editForm1 view.

Drag the field onto view grid1 to display the picture in the list of products.

Next, double-click on the Suppliers controller node. Enter the following in BLOB Adapter Configuration.

Note that the values above are not functional. Replace the highlighted parts with your own settings.

Make sure to save the controller.

Viewing the Results

On the toolbar, press Browse. Navigate to the Suppliers page and start editing a record. The new Logo field will accept file uploads. Click on the link and upload a file. The bar at the top of the screen will show a confirmation of upload and a thumbnail of the picture will be displayed. The File Name, Length, and Content Type utility fields will be updated accordingly.

The files can be seen in AWS Management Console.

To upload files larger than 4 MB, you will need to increase the application upload size limit.

Microsoft Azure Storage is a low-cost option that allows storing binary content in the cloud. Let’s implement storing of product pictures in the Northwind sample database. We will capture name, size, and content type of the picture file in the Products table. The actual pictures will be saved in Microsoft Azure Storage.

Setting Up Azure Storage

Navigate to http://azure.com and click on the Portal link in the top right corner to log in to your Azure account. If you do not have an account, a free three month trial is offered.

When the Management tool loads, click on the New button in the bottom left corner. Select Data Services | Storage | Quick Create option. Assign a URL for your new storage and press Create Storage Account.

When complete, click on the new storage account name in the list to view details. On the action bar displayed at the bottom, press Manage Access Keys. Copy one of the keys into the clipboard.

At the top of the form, click on Containers tab. Press Add Container at the bottom of the screen.

Assign a name to the container. If you do not expect the product pictures to be accessible to anonymous users, then leave Access property as “Private”. Click on the Check icon to save.

Adding Utility Fields to the Database

Start SQL Server Management Studio. In the Object Explorer, right-click on Databases / Northwind / Tables / dbo.Products, and press Design.

Add the following columns:

Save the changes. Switch to the generator and click on the project name. Select Refresh, check the box next to Products controller, and proceed to refresh the web app.

Configuring BLOB Field

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Products / Fields node, and press New Field.

Assign the following properties:

Save the field. Drag the new field node and drop it onto Products / Views / editForm1 to instantiate the field as a data field in the editForm1 view.

Drag the field onto view grid1 to display the picture in the list of products.

Next, double-click on the Products controller node. Enter the following in BLOB Adapter Configuration.

Note that the values above are not functional. Replace the highlighted parts with your own settings.

Make sure to save the controller.

Viewing the Results

On the toolbar, press Browse. Navigate to the Products page, and edit any record. Note that there is a Picture field which accepts files. Click on the link to upload a file and select a picture from your hard drive. A bar at the top of the page will announce completion of upload and the thumbnail of the picture will be displayed. The utility fields will be updated with the picture file name, length, and content type. If you do not want users to change any utility field values, configure the data fields as Static.

The thumbnail will display the file extension if the file is not an image.

The uploaded files are visible in Azure Management screen.

To upload files larger than 4 MB, you will need to increase the application upload size limit.