Question

我的目标是让用户和一个最新的入门用户创建，我试图在谷歌上解决但我失败了，所以你是我的最后一次机会。关于我尝试过的事情：

        DB::select('SELECT u.id, u.username, u.user_rating, 
                        u.avatar, u.created_at, e.id as e_id, e.title 
                        FROM users u
                        LEFT JOIN 
                        (
                            SELECT e.*
                            FROM entry e
                            LIMIT 1
                        ) entry AS e ON e.user_id = u.id
                        ORDER BY u.user_rating DESC 
                        LIMIT 10

我正在使用MySQL

修改

有了它，它不会给我错误，但它不会从加入任何条目：

DB::select('SELECT u.id, u.username, u.user_rating, 
          u.avatar, u.created_at, e.id as e_id, e.title 
           FROM users u
           LEFT JOIN 
           (
               SELECT e.*
               FROM entry e
               ORDER BY e.id DESC
               LIMIT 1
           ) AS e ON e.user_id = u.id
            ORDER BY u.user_rating DESC 
            LIMIT 10');

结果：

object(stdClass)#437 (7) {
["id"]=>
int(5002)
["username"]=>
string(6) "Nelosh"
["user_rating"]=>
int(77763)
["avatar"]=>
string(3) "its"
["created_at"]=>
string(19) "2013-12-16 19:20:23"
["e_id"]=>
NULL
["title"]=>
NULL

}

Answer 1

试试这个：

SELECT u.id, u.username, u.user_rating, u.avatar, u.created_at, e.id AS e_id, e.title 
FROM users u
LEFT JOIN (SELECT * FROM (SELECT * FROM entry e ORDER BY e.user_id, e.id DESC) AS e GROUP BY e.user_id) AS e ON e.user_id = u.id
ORDER BY u.user_rating DESC 
LIMIT 10;

或

SELECT u.id, u.username, u.user_rating, u.avatar, u.created_at, e.id AS e_id, e.title FROM users u LEFT JOIN (SELECT * FROM entry e ORDER BY e.user_id, e.id DESC) AS e ON e.user_id = u.id GROUP BY u.id ORDER BY u.user_rating DESC LIMIT 10;

修改:::

SELECT u.id, u.username, u.user_rating, u.avatar, u.created_at, e.id AS e_id, e.title FROM (SELECT u.id, u.username, u.user_rating, u.avatar, u.created_at FROM users u ORDER BY u.user_rating DESC LIMIT 10) AS u LEFT JOIN (SELECT e.id, e.user_id, e.title FROM entry e ORDER BY e.user_id, e.id DESC) AS e ON e.user_id = u.id GROUP BY u.id;

Answer 2

使用此：

 DB::select('SELECT u.id, u.username, u.user_rating, 
              u.avatar, u.created_at, e.id as e_id, e.title 
               FROM users u
               LEFT JOIN 
               (
                   SELECT e.*
                   FROM entry e
                   ORDER BY e.created_date DESC //add this condition also
                   LIMIT 1
               ) entry AS e ON e.user_id = u.id
                ORDER BY u.user_rating DESC 
                LIMIT 10

Answer 3

在子查询中，您需要添加ORDER BY以获取最后一个条目。如果你的e.id是自动增量的，你可以这样做：

...
SELECT e.*
FROM entry e
ORDER BY e.id DESC LIMIT 1
...

如何在连接表时选择1行

3 个答案: