汇总关系的雄辩查询

Question

我想通过模型关系的汇总值进行查询。 举例来说，我应该只会得到的帖子它有两个日期之间的最后一条评论。

SELECT posts.*, MAX(comments.created_at) 
as max FROM posts 
JOIN comments ON (comments.post_id = posts.id) 
GROUP BY posts.id HAVING max > '2014-01-01 00:00:00' AND max < '2014-02-01 00:00:00' 

Answer 1

取而代之的连接使用内置的方法：

// Assuming you have relations setup 
Post::whereHas('comments', function ($q) use ($from, $till) { 
    $q->groupBy('post_id') 
    ->havingRaw("max(created_at) between '{$from}' and '{$till}'"); 
})->get(); 

它会产生：

select * from `posts` where 
    (select count(*) from `comments` where `comments`.`post_id` = `posts`.`id` 
    group by `post_id` 
    having max(created_at) between '2014-01-01' and '2014-02-01' 
) >= 1 limit 1