Помогите реализовать рекурсивное дерево

# sqlite3

CREATE TABLE IF NOT EXISTS "comments"
(
	"comment_id" INTEGER PRIMARY KEY AUTOINCREMENT,
	"comment_parent" INTEGER DEFAULT 0,
	"comment_text" TEXT
);

INSERT INTO comments (comment_id, comment_parent, comment_text) VALUES ("1", "0", "first message");
INSERT INTO comments (comment_id, comment_parent, comment_text) VALUES ("2", "1", "first reply to first");
INSERT INTO comments (comment_id, comment_parent, comment_text) VALUES ("3", "1", "second reply to first");
INSERT INTO comments (comment_id, comment_parent, comment_text) VALUES ("4", "2", "first reply to second");
INSERT INTO comments (comment_id, comment_parent, comment_text) VALUES ("5", "2", "second reply to second");

WITH	clause AS 
	(
	SELECT	*
	FROM	comments
	WHERE	comment_parent = 0
	UNION ALL
	SELECT	child.*
	FROM	comments AS child
	JOIN	clause AS parent ON child.comment_parent = parent.comment_id
	)
SELECT	*
FROM	clause;

1|0|first message
2|1|first reply to first
3|1|second reply to first
4|2|first reply to second
5|2|second reply to second