Database Design Principles

Normalization

Organize data to reduce redundancy and improve integrity.

Normal Forms

• 1NF: Atomic values
• 2NF: No partial dependencies
• 3NF: No transitive dependencies

Relationships

Understand one-to-one, one-to-many, and many-to-many relationships.

-- User-Post relationship
CREATE TABLE posts (
  id INT PRIMARY KEY,
  user_id INT,
  title VARCHAR(255),
  FOREIGN KEY (user_id) REFERENCES users(id)
);

Design schemas that reflect real-world relationships.