Mysql SQL限制&；按交叉联接排序

我存储推特、推特用户，并将推特用户分组

我有以下4张桌子

推特：

tweet_id | user_id | created
-------------------------------
23452345 | 2345    | 2013-08-12
23456094 | 1234    | 2014-03-24
23097777 | 1234    | 2014-04-12
23948798 | 9999    | 2013-09-22

推特用户：

user_id | screen_name
------------------------
2345    | michael
1234    | david
9999    | not_interested

推特社交网站：

user_id | social_id
---------------------------
2345    | 34
9999    | 20
1234    | 80

社会福利类别：

social_id | category_id
-----------------------
34        | 3
20        | 6
80        | 3

我想看到在某个社交类别中出现的每个用户最早的推文。 我编写的以下SQL似乎不起作用。我每个

twitter\u用户都有一行，但是我没有看到最早的tweet

SELECT tu.screen_name as Handle, tw.created_at as Earliest
FROM twitter_users tu
    LEFT JOIN tweets tw
        ON tu.user_id = tw.user_id
    LEFT JOIN twitter_social ts
        ON ts.user_id = tu.user_id
    LEFT JOIN social_categories cs
        ON ts.social_id = cs.social_id
WHERE cs.category_id=3
GROUP BY Handle
ORDER BY Earliest ASC

编辑
我希望有如下结果

Handle  | Earliest
---------------------
david   | 2014-03-24
michael | 2013-08-12

如果你想要最早的，它不是ASC（升序）

它应该是DESC（降序）

试试这个

SELECT tu.screen_name as Handle, min(tw.created_at) as Earliest
FROM twitter_users tu
    LEFT JOIN tweets tw
        ON tu.user_id = tw.user_id
    LEFT JOIN twitter_social ts
        ON ts.user_id = tu.user_id
    LEFT JOIN social_categories cs
        ON ts.social_id = cs.social_id
WHERE cs.category_id=3
GROUP BY tu.screen_name
ORDER BY Earliest ASC

尽可能早地尝试
MIN（tw.created_at）
是的，这样做了@AbhikChakraborty谢谢。我原以为MIN在查询中太晚了，但它起作用了！这应该是一个评论，而不是一个答案。我的意思是最早的，而不是最近的。
ORDER BY Earliest DESC

SELECT tu.screen_name as Handle
    ,MIN(tw.created_at) as Earliest
FROM twitter_users tu
LEFT JOIN tweets tw
    ON tu.user_id = tw.user_id
LEFT JOIN twitter_social ts
    ON ts.user_id = tu.user_id
LEFT JOIN social_categories cs
    ON ts.social_id = cs.social_id
WHERE cs.category_id=3
GROUP BY tu.screen_name
ORDER BY Earliest ASC

SELECT tu.screen_name as Handle, tw.created_at as Earliest
FROM twitter_users tu
LEFT JOIN tweets tw
    ON tu.user_id = tw.user_id
LEFT JOIN twitter_social ts
    ON ts.user_id = tu.user_id
LEFT JOIN social_categories cs
    ON ts.social_id = cs.social_id
WHERE cs.category_id=3
GROUP BY Handle
ORDER BY Earliest DESC
LIMIT 1

SELECT tu.screen_name as Handle, min(tw.created_at) as Earliest
FROM twitter_users tu
    LEFT JOIN tweets tw
        ON tu.user_id = tw.user_id
    LEFT JOIN twitter_social ts
        ON ts.user_id = tu.user_id
    LEFT JOIN social_categories cs
        ON ts.social_id = cs.social_id
WHERE cs.category_id=3
GROUP BY tu.screen_name
ORDER BY Earliest ASC