mysql – 需要一些关于此查询的帮助获取我和我所有朋友的所有状态及其相关评论
作者：互联网
我有好几天处理这个查询,但无法按照我的意愿使用它.这篇文章与这个Several values from different tables有关,我很难找到解决方案,但我完全错了并丢失:(.所以基本上是与其他帖子相同的架构：5个表：default_users,default_profiles,default_status,default_comment和default_friend.这个是每个的SQL：
default_comment
CREATE TABLE `default_comment` (
`comment_id` int(11) NOT NULL AUTO_INCREMENT,
`friend_id` int(11) NOT NULL,
`message` text COLLATE utf8_unicode_ci NOT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`status_id` int(11) NOT NULL,
`device` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`comment_id`)
) ENGINE=InnoDB AUTO_INCREMENT=13007 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
default_friend
CREATE TABLE `default_friend` (
`friend_id` int(8) NOT NULL,
`user_id` int(8) NOT NULL,
`is_suscriber` tinyint(1) NOT NULL DEFAULT '1',
`privacy` tinyint(1) NOT NULL DEFAULT '0',
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`friend_list_id` int(4) NOT NULL,
`approved` tinyint(1) NOT NULL DEFAULT '0'
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
default_profiles
CREATE TABLE `default_profiles` (
`id` int(9) NOT NULL AUTO_INCREMENT,
`created` datetime DEFAULT NULL,
`updated` datetime DEFAULT NULL,
`created_by` int(11) DEFAULT NULL,
`ordering_count` int(11) DEFAULT NULL,
`user_id` int(11) unsigned NOT NULL,
`display_name` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`first_name` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`last_name` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`updated_on` int(11) unsigned DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `user_id` (`user_id`)
) ENGINE=MyISAM AUTO_INCREMENT=10004 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
default_status
CREATE TABLE `default_status` (
`status_id` int(11) NOT NULL AUTO_INCREMENT,
`message` text COLLATE utf8_unicode_ci NOT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`privacy` tinyint(1) DEFAULT NULL,
`user_id` int(11) NOT NULL,
`is_reply` tinyint(1) NOT NULL DEFAULT '0',
`device` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`status_id`)
) ENGINE=InnoDB AUTO_INCREMENT=13005 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
default_users
CREATE TABLE `default_users` (
`id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
`email` varchar(60) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`password` varchar(100) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`salt` varchar(6) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`group_id` int(11) DEFAULT NULL,
`ip_address` varchar(16) COLLATE utf8_unicode_ci DEFAULT NULL,
`active` int(1) DEFAULT NULL,
`activation_code` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL,
`created_on` int(11) NOT NULL,
`last_login` int(11) NOT NULL,
`username` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL,
`forgotten_password_code` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL,
`remember_code` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `email` (`email`)
) ENGINE=InnoDB AUTO_INCREMENT=10004 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='Registered User Information'
所以我构建了这个查询
SELECT DISTINCT
u.id AS user_id,
u.email,
p.display_name,
p.first_name,
p.last_name,
s.status_id,
s.message,
f.friend_id,
f.user_id,
UNIX_TIMESTAMP(s.created_at) AS created_at
FROM
default_users u
LEFT JOIN
default_friend f ON ((f.friend_id = 1 OR f.user_id = 1) AND f.approved = 1)
LEFT JOIN
default_status s ON (u.id = s.user_id OR f.friend_id = s.user_id OR f.user_id = s.user_id)
LEFT JOIN
default_profiles p ON (s.user_id = p.user_id)
WHERE
u.id = 1
ORDER BY s.created_at DESC
LIMIT 0 , 10
这就是结果：
+---------+---------------------+--------------------+-----------------------------+----------------------------+-----------+------------------------------------------------------------------------------------------------------+-----------+---------+------------+
| user_id | email | display_name | first_name | last_name | status_id | message | friend_id | user_id | created_at |
+---------+---------------------+--------------------+-----------------------------+----------------------------+-----------+------------------------------------------------------------------------------------------------------+-----------+---------+------------+
| 1 | reynierpm@gmail.com | Reynier Perez Mira | Reynier | Perez Mira | 12686 | c1aqq8fy7lp8c2gvph4j3mwllqrtvohf2oto2dsgv6qkgsdf98w7029vpriju7p87h0zvrt7nqrp7v61v3zw7a5zg96sl0mfts4w | 2 | 1 | 1345055203 |
| 1 | reynierpm@gmail.com | Reynier Perez Mira | Reynier | Perez Mira | 12686 | c1aqq8fy7lp8c2gvph4j3mwllqrtvohf2oto2dsgv6qkgsdf98w7029vpriju7p87h0zvrt7nqrp7v61v3zw7a5zg96sl0mfts4w | 1 | 3 | 1345055203 |
| 1 | reynierpm@gmail.com | Reynier Perez Mira | Reynier | Perez Mira | 12686 | c1aqq8fy7lp8c2gvph4j3mwllqrtvohf2oto2dsgv6qkgsdf98w7029vpriju7p87h0zvrt7nqrp7v61v3zw7a5zg96sl0mfts4w | 1 | 4315 | 1345055203 |
| 1 | reynierpm@gmail.com | Reynier Perez Mira | Reynier | Perez Mira | 12686 | c1aqq8fy7lp8c2gvph4j3mwllqrtvohf2oto2dsgv6qkgsdf98w7029vpriju7p87h0zvrt7nqrp7v61v3zw7a5zg96sl0mfts4w | 6380 | 1 | 1345055203 |
| 1 | reynierpm@gmail.com | Demo | Demo | Demo | 10484 | ivp1e40f350bf6ifplzsd560k6e5mvgvdq91q7j2k5oldraoftbd2k2eirtdihh7fbqwq2mkohqi05d3fw0sawvqmabah979updo | 2 | 1 | 1345055064 |
| 1 | reynierpm@gmail.com | User 1 | User | User | 10494 | arstvbkjrea725bea4mv1kv1qaelt669n7mequh5j6n5uzh8a3voy7w6lvebphrhkhnks9fzos46p8sqptud1mb3wysjpge653qe | 1 | 3 | 1345055064 |
| 1 | reynierpm@gmail.com | user502bc8a4942d1 | user502bc8a4942d1-firstname | user502bc8a4942d1-lastname | 7796 | vmkhv266hu8s7czpy1j2m1cvi3j1i3jr35hl76fsdqdv1cacv5etylls3q6yqrm7r2nrymjcqrvtzu267huajs5g9j9t3kdz6f9l | 1 | 4315 | 1345054882 |
| 1 | reynierpm@gmail.com | user502bc90a00ba4 | user502bc90a00ba4-firstname | user502bc90a00ba4-lastname | 6103 | c3mmq89ucbcjd0w1pdak0tgtioyfy5loa3z18ecmkwukusojbr6qwosbham8d132fzq1pn6ei3h5dgoabyvytyyuiqm2k09fmudy | 6380 | 1 | 1345054774 |
| 1 | reynierpm@gmail.com | Demo | Demo | Demo | 3828 | hky500btaj5rq96inod22k1zpyh1uz65892mwanuloqkqgjo1h3u2f0ikery3pe3olwoqbqq08t301vqpuhirvddp3lq6w5ppoep | 2 | 1 | 1345054631 |
| 1 | reynierpm@gmail.com | Reynier Perez Mira | Reynier | Perez Mira | 2364 | zfe25at726i4bsju21v3ipcpp6bhetdrqva7m4ceh0k2pcdj6equbnq89mlg892eh5eqq1l1514qir76pqq5u7qnqyai6dqnv45n | 2 | 1 | 1345054536 |
+---------+---------------------+--------------------+-----------------------------+----------------------------+-----------+------------------------------------------------------------------------------------------------------+-----------+---------+------------+
10 rows in set (0.08 sec)
但如果我运行此查询以获取我的朋友：
SELECT
*
FROM
default_friend
WHERE
user_id = 1 OR friend_id = 1
这是结果
+-----------+---------+--------------+---------+---------------------+----------------+----------+
| friend_id | user_id | is_suscriber | privacy | created_at | friend_list_id | approved |
+-----------+---------+--------------+---------+---------------------+----------------+----------+
| 2 | 1 | 1 | 0 | 2012-08-13 13:46:11 | 0 | 1 |
| 1 | 3 | 1 | 0 | 2012-08-14 14:46:11 | 0 | 1 |
| 1 | 4315 | 1 | 0 | 2012-08-15 11:57:51 | 0 | 1 |
| 6380 | 1 | 1 | 0 | 2012-08-15 11:58:47 | 0 | 1 |
+-----------+---------+--------------+---------+---------------------+----------------+----------+
4 rows in set (0.01 sec)
另外如果我运行这个来获取我和我所有朋友的消息：
SELECT
*
FROM
default_status
WHERE
user_id = 1 OR user_id = 3 OR user_id = 4315 OR user_id = 6380
我得到了这个结果：
+-----------+------------------------------------------------------------------------------------------------------+---------------------+---------+---------+----------+--------+
| status_id | message | created_at | privacy | user_id | is_reply | device |
+-----------+------------------------------------------------------------------------------------------------------+---------------------+---------+---------+----------+--------+
| 1 | dasdasdasdasdasd | 2012-08-13 15:15:37 | NULL | 1 | 0 | |
| 3 | dasdsad344hbvnbnhjhgjhjghjhj | 2012-08-13 17:24:53 | NULL | 1 | 0 | |
| 4 | dasdsad344hbvnbnhjhgjhjghjhjsdfsdfsdfsdfdsfsdfsdfsdfsdfsdfsdfsdfsdfsdfsdfsdf | 2012-08-13 17:24:53 | NULL | 3 | 0 | |
| 834 | pgmafjmzicgdqu1fo0fv3sg4qipq4dm3qnubpo4gpyfz5y7q0p9kl75c18c9tsr01u92fqfoyyw12vl7zn1bht4vhnyf2b5cldrp | 2012-08-15 13:43:57 | NULL | 3 | 0 | |
| 2364 | zfe25at726i4bsju21v3ipcpp6bhetdrqva7m4ceh0k2pcdj6equbnq89mlg892eh5eqq1l1514qir76pqq5u7qnqyai6dqnv45n | 2012-08-15 13:45:36 | NULL | 1 | 0 | |
| 6103 | c3mmq89ucbcjd0w1pdak0tgtioyfy5loa3z18ecmkwukusojbr6qwosbham8d132fzq1pn6ei3h5dgoabyvytyyuiqm2k09fmudy | 2012-08-15 13:49:34 | NULL | 6380 | 0 | |
| 7796 | vmkhv266hu8s7czpy1j2m1cvi3j1i3jr35hl76fsdqdv1cacv5etylls3q6yqrm7r2nrymjcqrvtzu267huajs5g9j9t3kdz6f9l | 2012-08-15 13:51:22 | NULL | 4315 | 0 | |
| 10494 | arstvbkjrea725bea4mv1kv1qaelt669n7mequh5j6n5uzh8a3voy7w6lvebphrhkhnks9fzos46p8sqptud1mb3wysjpge653qe | 2012-08-15 13:54:24 | NULL | 3 | 0 | |
| 12686 | c1aqq8fy7lp8c2gvph4j3mwllqrtvohf2oto2dsgv6qkgsdf98w7029vpriju7p87h0zvrt7nqrp7v61v3zw7a5zg96sl0mfts4w | 2012-08-15 13:56:43 | NULL | 1 | 0 | |
+-----------+------------------------------------------------------------------------------------------------------+---------------------+---------+---------+----------+--------+
9 rows in set (0.02 sec)
所以在这个解释之后我的第一个查询出了什么问题？我得到的结果是第一个查询中没有的其他选择？ (加入的那个),任何帮助或建议？非常重要的测试文件在我的Dropbox https://www.dropbox.com/s/tu4rb7osppyd8un/comvivem_db.sql上
解决方法:
好的,所以根据我们的对话,如果你确定在创建朋友的请求时你也在另一个方向创建一个条目:(即Friend_A询问Friend_B,但你还需要Friend_B和Friend_A之间的关系)然后你可以运行以下查询以获取您需要的结果：
select distinct
s.user_id,
u.username,
p.display_name,
p.first_name,
p.last_name,
s.message
from default_status as s
join default_friend as f on f.user_id = s.user_id
join default_users as u on u.id = s.user_id
join default_profiles as p on p.user_id = u.id
where (f.user_id = 1 or f.friend_id = 1)
and f.approved = 1
order by s.created_at desc;
这也将使得更容易获得所有朋友的列表：
select *
from default_users as u
join default_friends as f on f.friend_id = u.id
where f.user_id = 1;
只需记住在默认的friends_table中放置一个索引over user_id和friend_id,否则你会发现你的查询可能需要一段时间：
create unique index idx_friend on default_friend(user_id,friend_id);
我希望这可以帮助你.
标签：query-performance,mysql,mysql-5-5,query 来源： https://codeday.me/bug/20190807/1606532.html