Unit 4: Work Integrated Learning IT – DMAIndustry Domains & E-Commerce Database Architecture
Definitive study guide based on Pages 144–157 of the CBSE Class XII Student Handbook. Master database applications across 10 corporate domains, entity-relationship schemas for the XYZ Shopping Website (Category, Product, Seller, Customer, Wishlist, Order, Shipment, Payment), and object-oriented Java skeleton classes for business data operations.
CATEGORY, PRODUCT, CUSTOMER, SELLER, WISH_LIST (composite PK), ORDER, SHIPMENT, and PAYMENT.insert_(), delete_(), modify_(), and display_() methods executing parameterized SQL statements.Database Applications Across 10 Key Industry Sectors
Case Study: XYZ Shopping Website Database Architecture
The XYZ Shopping Website provides 24x7 online access across categories (books, apparel, stationery, kitchen appliances, and electronics). The backend database requires eight distinct entities with clear primary and foreign key constraints:
| Table Name | Primary Key | Foreign Keys | Attributes & Purpose |
|---|---|---|---|
| CATEGORY | Category_id | None | Name, Description. Catalogs product taxonomy. |
| PRODUCT | Product_id | Category_id, Seller_id | Name, Price, Quantity, Discount, Brand, Color, Size, Description. |
| CUSTOMER | Customer_id | None | Password, First_name, Last_name, Address, Email_id, Contact_num. |
| SELLER | Seller_id | None | Rating (1 to 5). Stores vendor performance. |
| WISH_LIST | (Customer_id, Product_id) | Customer_id, Product_id | Composite key bridging customer to saved items. |
| ORDER | Order_id | Customer_id, Product_id, Shipment_id | Order_date, Current_status (Pending or Delivered). |
| SHIPMENT | Shipment_id | None | Details (dispatch warehouse), Shipment_date. |
| PAYMENT | Payment_id | Order_id | Payment_amount, Payment_date, Mode (Card, Net Banking, COD). |
Java DAO Skeleton Example for Table PRODUCT (Figure 4.3(l))
package shopping_application;
public class Product {
// Executes SQL INSERT INTO PRODUCT VALUES(...)
public void insert_product(String prod_tuple[]) { /* DB write */ }
// Executes SQL DELETE FROM PRODUCT WHERE Product_id = id
public void delete_product(int prod_id) { /* DB delete */ }
// Executes SQL UPDATE PRODUCT SET attr = new WHERE Product_id = id
public void modify_product(int prod_id, String attr, String newVal) { /* DB update */ }
// Executes SQL SELECT * FROM PRODUCT WHERE Product_id = id
public void display_product(int prod_id) { /* DB query */ }
}
Official Unit 4 Practice Questions
Q1. In the XYZ Shopping Website database design, which table uses a composite primary key consisting of two foreign keys?
Q2. Which of the following attributes is defined as a Foreign Key in the 'ORDER' table pointing to the shipment record?
Q3. Why is the 'SHIPMENT' entity maintained in a separate table rather than storing dispatch details directly inside the 'ORDER' table?
Q4. When a customer selects 'Cash on Delivery' (COD) for payment, how is the 'Payment_date' attribute in the PAYMENT table initialized?
Q5. Which Java method in class 'Category' is invoked when an administrator modifies the description of an existing product category?
Q6. Which industry work area maintains records of Call Detail Records (CDR), data consumption, and prepaid/postpaid subscriber plans?
Q7. In the 'PRODUCT' table schema, which attribute links the product to its merchant offering it for sale?
Q8. If a product is sold by multiple independent sellers at different prices and ratings, how can this relationship be modeled?
Q9. What is the primary role of a Domestic IT Helpdesk Assistant / Desktop Management Assistant (DMA)?
Q10. What sequence of user events occurs during Order Completion in the shopping portal (Figure 4.3(r))?
Unit 4 Work Integrated Learning FAQs (AEO & Board Focus)
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