Converting a raw query to Laravel query builder - laravel

Question

I have the following MySQL query which fetches a list of the last 9 authors to write a post and lists them in order of the date of the last post they wrote.
It's working properly but I'd like to re-write it using the Laravel Query Builder. Here is the query at the moment:
$authors = DB::select("
SELECT
`a`.`id`,
`a`.`name`,
`a`.`avatar`,
`a`.`slug` AS `author_slug`,
`p`.`subheading`,
`p`.`title`,
`p`.`slug` AS `post_slug`,
`p`.`summary`,
`p`.`published_at`
FROM
`authors` AS `a`
JOIN
`posts` AS `p`
ON `p`.`id` =
(
SELECT `p2`.`id`
FROM `posts` AS `p2`
WHERE `p2`.`author_id` = `a`.`id`
ORDER BY `p2`.`published_at` DESC
LIMIT 1
)
WHERE
`a`.`online` = 1
ORDER BY
`published_at` DESC
LIMIT 9
");
I understand the basics of using the query builder, but there doesn't appear to be anything in the Laravel docs that allows for me to JOIN a table ON a SELECT.
Can anyone suggest a way that I can write this query using the Laravel Query builder, or perhaps suggest a way that I can rewrite this query to make it easier to structure with the query builder?

Answer 1

Try to do like this
$data = DB::table('authors')
->select(
'a.id',
'a.name',
'a.avatar',
'a.slug AS author_slug',
'p.subheading',
'p.title',
'p.slug AS post_slug',
'p.summary',
p.published_at')
->from('authors AS a')
->join('posts AS p', 'p.id', '=', DB::raw("
(
SELECT p2.id FROM posts AS p2
WHERE p2.author_id = b.id
ORDER BY p2.published_at
DESC LIMIT 1
)"))
->where('a.online', 1)
->limit(9)
->orderBy('p.published_at', 'desc')
->get();