C H A P T E R 4 Designing Database E-Commerce Hassanin M. Al-Barhamtoshy

How This Chapter Is Structured The main topics we’ll touch on in this chapter are: 1.Analyzing the requirement of the database and the functionality it should support 2.Creating the database structures for the application 3.Implementing the business tier objects required to make the system run, and putting a basic but functional error-handling strategy in place 4.Implementing a functional UI for the system

What Does a Product Catalog Look Like?  We need the following file entities:  Products  Categories  Customers  Orders

Database Designing The major tables in e-Commerce database, as the following: 1- Products Table Name Category Name Description Vendor name Vendor address Vendor phone number Price Image file name

Database Designing 2- Category Name 3- Customers Last Name First Name Address City State Zip Code Phone Number Credit Card Number

Database Designing 4- Order Order number Date Customer Product Quantity Price Subtotal Shipping Tax Total

After the key columns have been added, the list looks like this: Products Product ID (primary key) Name Category ID (foreign key) Category Name Description Price Image file name Vendor ID (foreign key) Vendor Vendor ID (primary key) Name Address City State Zip Code Phone Number

Category Category ID (primary key) Name Customers Last Name First Name Address City State Zip Code Phone Number (primary key) Credit Card Number Order Order number (primary key) Date

Order Order number (primary key) Date Customer ID (foreign key) Product ID (foreign key) Quantity Price Subtotal Shipping Tax Total

Entity Relation Database

Building a Product Catalog Application This application’s user interface has just three pages: 1.Default.aspx displays a list of products for a category selected by the user. 2.Product.aspx displays details about a specific product selected by the user. 3.Cart.aspx is displayed when the user chooses to purchase a product.

The user interface for the Product Catalog application.

The Product List page.

The Product Detail page.

The Cart page

Designing the Product Database It consists of three tables: Categories Products FeaturedProducts

The Categories table

The Products table

The Featured Products table

Creating the database sqlcmd -S localhost\SQLExpress -i CreateProducts.sql The CreateProducts.sql script USE master GO IF EXISTS(SELECT * FROM sysdatabases WHERE name=’Products’) DROP DATABASE Products GO CREATE DATABASE Products ➝ 3 ON (NAME= Product, FILENAME= ‘C:\APPS\Products.mdf’, SIZE=10 ) GO

Creating the database USE Products GO CREATE TABLE Categories ( catid VARCHAR(10) NOT NULL, name VARCHAR(50) NOT NULL, [desc] VARCHAR(MAX) NOT NULL, PRIMARY KEY(catid) ) GO CREATE TABLE Products (productid VARCHAR(10) NOT NULL, catid VARCHAR(10) NOT NULL, name VARCHAR(50) NOT NULL, shorttext VARCHAR(MAX) NOT NULL, longtext VARCHAR(MAX) NOT NULL, price MONEY NOT NULL, thumbnail VARCHAR(40) NOT NULL, image VARCHAR(40) NOT NULL, PRIMARY KEY(productid), FOREIGN KEY(catid) REFERENCES Categories(catid) ) GO

Creating the database CREATE TABLE FeaturedProducts ( productid VARCHAR(10) NOT NULL, featuretext VARCHAR(MAX) NOT NULL, saleprice MONEY NOT NULL, PRIMARY KEY(productid), FOREIGN KEY(productid) REFERENCES Products(productid) ) GO

Adding Logic to the Site The following paragraphs describe the highlights of this script: 1.Sets the database context to master. This is usually the default context, but it’s a good idea to set it just in case. 2.Deletes the existing Products database if it exists. 3.Creates a database named Products. The database file will be created in the C:\Apps directory. You should change this location if you want to place the database file in a different folder. 4.Creates the Categories table. 5.Note that the column name desc is a SQL keyword, so it must be enclosed in brackets. 6.Creates the Products table. 7.Creates the FeaturedProducts table.

sqlcmd -S localhost\SQLExpress -i InsertProducts.sql Once again, you’ll need to change the server name if you’re not running SQL Server Express on your own computer. You’ll know the script works if you see a series of messages like this one: (1 rows affected) Adding some test data

The application must perform the following queries: 1.Retrieve all rows from the Categories table to fill the drop-down list on the Default.aspx page so the user can select a product. 2.Retrieve all rows from the FeaturedProducts table to display at the top of the Default.aspx page. Note that some data is also required from the Products table, so this query requires a join. 3.Retrieve all products for a given category, including the sale price indicated in the FeaturedProducts table. 4.Retrieve all data for a specified product to display on the Product.aspx page. Note that this query must also retrieve the sale price from the FeaturedProducts table. Querying the database

The query to retrieve all rows from the Categories table uses this SQL statement: SELECT catid, name, [desc] FROM Categories ORDER BY name Querying the database

The query to retrieve the featured product rows requires a join to retrieve data from the FeaturedProducts table as well as the Products table: SELECT FeaturedProducts.productid, FeaturedProducts.featuretext, FeaturedProducts.saleprice, Products.name, Products.price FROM FeaturedProducts INNER JOIN Products ON FeaturedProducts.productid = Products.productid Querying the database

The query to retrieve the products for a given category also requires a join: SELECT Products.productid, Products.catid, Products.name, Products.shorttext, Products.longtext, Products.price, Products.image, Products.thumbnail, FeaturedProducts.saleprice FROM Products LEFT OUTER JOIN FeaturedProducts ON Products.productid = FeaturedProducts.productid WHERE (Products.catid Querying the database

The last query used by the program retrieves the data for a specific product: SELECT Products.productid, Products.catid, Products.name, Products.shorttext, Products.longtext, Products.price, Products.image, FeaturedProducts.saleprice, FeaturedProducts.featuretext FROM Products LEFT OUTER JOIN FeaturedProducts ON Products.productid = FeaturedProducts.productid WHERE (Products.productid Querying the database

The connection string used to access the Products database is stored in the application’s web.config file, like this: <add name=”ConnectionString” connectionString=”Data Source=localhost\SQLExpress; Initial Catalog=Products;Integrated Security=True”/> Connecting to the database

The last query used by the program retrieves the data for a specific product: SELECT Products.productid, Products.catid, Products.name, Products.shorttext, Products.longtext, Products.price, Products.image, FeaturedProducts.saleprice, FeaturedProducts.featuretext FROM Products LEFT OUTER JOIN FeaturedProducts ON Products.productid = FeaturedProducts.productid WHERE (Products.productid Querying the database

Downloading the Code Once you download the code, just decompress it with your favorite compression tool. Alternately, you can go to the main Wrox code download page at: to see the code available for this book and all other Wrox books. You can also download the examples from the Wrox Books Web site at: WileyCDA/WileyTitle/productCd html

Quiz # 2 Design an ERD (Entity Relation Database) for e-Learning Application), includes the following: E-Learning Table names. Tables Structure. Tables Relation.