mysql 查找叶节点路径

CREATE TABLE categories (
    id INT PRIMARY KEY,
    name VARCHAR(255),
    parent_id INT,
    FOREIGN KEY (parent_id) REFERENCES categories(id)
);

INSERT INTO categories (id, name, parent_id) VALUES
(1, 'Electronics', NULL),
(2, 'Computers', 1),
(3, 'Laptops', 2),
(4, 'Desktops', 2),
(5, 'Smartphones', 1),
(6, 'Accessories', 1),
(7, 'Cases', 6),
(8, 'Chargers', 6);

WITH RECURSIVE category_path AS (
    SELECT id, name, parent_id, CONCAT(name) AS path
    FROM categories
    WHERE parent_id IS NULL
    UNION ALL
    SELECT c.id, c.name, c.parent_id, CONCAT(cp.path, ' > ', c.name) AS path
    FROM categories c
    JOIN category_path cp ON c.parent_id = cp.id
)
SELECT * FROM category_path WHERE id NOT IN (SELECT parent_id FROM categories);