Как составить двойной MYSQLi запрос?
схематично так:SELECT
	blog.Blogtitle,
	comments.*
FROM
	blog
JOIN
	comments ON comments.idl = blog.id
Все я сам понял $sql='SELECT * FROM comments WHERE idl IN (SELECT id FROM blog WHERE Blogavtor = "'.$_SESSION['ulogin'].'") ORDER BY id DESC LIMIT 0, 20';