How can one optimize database design to avoid having a large number of empty fields in PHP applications?

To optimize database design and avoid having a large number of empty fields in PHP applications, one can use normalization techniques to break down tables into smaller, related tables. This helps reduce redundancy and ensures that each field contains meaningful data. Additionally, using proper data types and constraints can help enforce data integrity and prevent empty fields.

CREATE TABLE users (
    id INT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100) NOT NULL,
    password VARCHAR(255) NOT NULL
);

CREATE TABLE user_details (
    id INT PRIMARY KEY,
    user_id INT,
    full_name VARCHAR(100) NOT NULL,
    age INT NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users(id)
);