PHP Tips: Elegantly Implement Infinite Classification

In PHP development, achieving unlimited classification is a common requirement. This article will introduce an elegant method to achieve infinite classification and provide the corresponding source code.

1. Database table design

First, we need to design a database table to store classification information. The table structure is as follows:

CREATE TABLE categories (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(255) NOT NULL,
    parent_id INT
);

In this tableÿ