Question

我正在尝试编写一些sql来访问用户个人资料以及他们访问其他个人资料。

数据库架构

mysql> desc user_views;
+------------+--------------+------+-----+---------+-------+
| Field      | Type         | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+-------+
| user_id    | mediumint(8) | NO   | PRI | 0       |       |
| visitor_id | mediumint(8) | NO   | PRI | 0       |       |
| created_at | datetime     | NO   |     | NULL    |       |
+------------+--------------+------+-----+---------+-------+    

mysql> desc users;
+--------------------+----------------+------+-----+---------+----------------+
| Field              | Type           | Null | Key | Default | Extra          |
+--------------------+----------------+------+-----+---------+----------------+
| id                 | mediumint(8)   | NO   | PRI | NULL    | auto_increment |
| first_name         | varchar(255)   | YES  |     | NULL    |                |
| last_name          | varchar(255)   | YES  |     | NULL    |                |
| email_address      | varchar(255)   | NO   | UNI | NULL    |                |
| username           | varchar(128)   | NO   | UNI | NULL    |                |
| algorithm          | varchar(128)   | NO   |     | sha1    |                |
| salt               | varchar(128)   | YES  |     | NULL    |                |
| password           | varchar(128)   | YES  |     | NULL    |                |
| is_active          | tinyint(1)     | YES  | MUL | 1       |                |
+--------------------+----------------+------+-----+---------+----------------+

我的访问者SQL

仅向用户显示一次。例如，如果我刷新用户A的个人资料3次，将显示最近的访问次数。我想跟踪每次访问，以便告诉用户他们独特的观点和总体观点。

SELECT v.visitor_id FROM user_views v, users u, users u2
WHERE v.user_id = :user_id AND v.visitor_id != :user_id
AND u.id = v.user_id AND u2.id = v.visitor_id
AND u.is_active = 1 AND u2.is_active = 1
AND NOT EXISTS 
   (
     SELECT * FROM user_profile_view v2 
     WHERE v2.visitor_id = v.visitor_id  
     AND v2.created_at > v.created_at
   )
ORDER BY v.created_at DESC LIMIT 0, 10

访问过的SQL

再次相同。用户只会显示一次。

SELECT v.user_id FROM user_views v, users u, users u2 
WHERE v.user_id != :visitor_id AND v.visitor_id = :visitor_id
AND u.id = v.user_id AND u2.id = v.visitor_id
AND u.is_active = 1 AND u2.is_active = 1
AND NOT EXISTS 
  (
    SELECT * FROM users_view v2
    WHERE v2.user_id = v.user_id AND v2.created_at > v.created_at
  )
GROUP BY v.user_id
ORDER BY v.created_at DESC LIMIT 0, 10

SQL工作正常，但我想知道您是否认为SQL可以改进，或者我应该以更有效的方式编写它。

MySQL用户个人资料访问者和访问

0 个答案: