Bits of .NET

📊 Normalization = Organized Data

Bad design = duplicate data, anomalies. Normalization organizes data. 1NF, 2NF, 3NF — reduce redundancy, improve integrity.

📝 First Normal Form (1NF)

❌ Not 1NF (repeating groups)
Order: 1, Customer: Alice, Products: Laptop, Phone, Tablet

✅ 1NF (atomic values, separate rows)
OrderID  Customer  Product
1        Alice     Laptop
1        Alice     Phone
1        Alice     Tablet

✅ 1NF: Each cell has single value
✅ 1NF: Each row is unique

🎯 Second and Third Normal Form

✅ 2NF: In 1NF + all non-key columns depend on entire primary key
(For tables with composite keys)

❌ 2NF violation:
OrderID  ProductID  ProductName  Price
1        101        Laptop       999
1        102        Phone        599

✅ 2NF fix (split tables):
Orders: OrderID, Customer
OrderItems: OrderID, ProductID
Products: ProductID, ProductName, Price

✅ 3NF: In 2NF + no transitive dependency
❌ 3NF violation:
EmployeeID  Department  DepartmentHead
1           IT          John
2           Sales       Mary

✅ 3NF fix (split tables):
Employees: EmployeeID, DepartmentID
Departments: DepartmentID, DepartmentName, DepartmentHead

💡 Benefits

• Reduces data redundancy
• Prevents anomalies (insert, update, delete)
• Improves data integrity
• Easier maintenance
• Better performance (with proper indexes)