Question 1
Why split customer and order details into separate tables?
It reduces repeated customer data, makes updates safer and allows each order to be linked to one customer.
What to learn
Relate tables instead of repeating the same information. Define one-to-one, one-to-many or many-to-many relationships, set field properties and use referential integrity to protect consistency.
- A relationship connects matching key fields in different tables.
- One-to-many is common: one customer can have many orders.
- A junction table can represent a many-to-many relationship.
- Referential integrity prevents invalid references to records that do not exist.
Practical activity
Create Customer and Order tables. Use CustomerID as the primary key in Customer and a foreign key in Order. Link them and test what happens when a referenced customer is deleted.
Use your school’s prescribed software version and teacher instructions. Keep personal information out of public practice files.
Solved CBSE-style questions
These questions and answers are original practice written for this guide; they are not copied from past papers.
Question 2
What does referential integrity protect?
It helps ensure that a foreign key refers to an existing record, preventing orphaned or invalid relationships.
Question 3
How can a many-to-many relationship be represented?
Use a junction table containing foreign keys for both related tables, such as StudentCourse linking students and courses.
Revision checklist
- Can I explain the key terms without memorising a definition alone?
- Can I complete the listed practical task and describe each step?
- Can I apply the idea to a new example and explain why my answer works?
Aligned to the CBSE 2026–27 syllabus outline. Check the official subject curriculum and your school’s textbook/material for the prescribed scope.