PHP函数

Question

这是我用来取消关注用户的功能。

删除

INSERT

更新

multi_query

PHP函数

// 'By' is the array that hold logged user and 'followed' is the user id which we are going to unfollow
function unFollowUser($followed,$by) {
    $following = $this->getUserByID($followed);// Return fetch_assoc of user row
    if(!empty($following['idu'])) { // if user exists

        // return user followers as number of rows
        $followers = $this->db->real_escape_string($this->numberFollowers($following['idu'])) - 1;  

        $followed_esc = $this->db->real_escape_string($following['idu']);
        $by_user_esc = $this->db->real_escape_string($by['idu']);

        // delete relationship
        $query = "DELETE FROM `relationships` WHERE `relationships`.`user2` = '$followed_esc' AND `relationships`.`user1` = '$by_user_esc' ;" ;

        // delete notification (user started following you )
        $query.= "DELETE FROM `notifications` WHERE `notifications`.`not_from` = '$by_user_esc' AND `notifications`.`not_to` = '$followed_esc' ;" ;

        // Insert a new notification( user has unfollowed you)
        $query.= "INSERT INTO `notifications`(`id`, `not_from`, `not_to`, `not_content_id`,`not_content`,`not_type`,`not_read`, `not_time`) VALUES (NULL, '$by_user_esc', '$followed_esc', '0','0','5','0', CURRENT_TIMESTAMP) ;" ;

        // update user followers (-1)
        $query .= "UPDATE `users` SET `followers` = '$followers' WHERE `users`.`idu` = '$followed_esc' ;" ;

        if($this->db->multi_query($query) === TRUE) {
            return 1;
        } else {
            return 0;
        }
    } else {
        return 0;
    }
}

表结构

--
-- Table structure for table `notifications`
--

CREATE TABLE IF NOT EXISTS `notifications` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `not_from` int(11) NOT NULL,
  `not_to` int(11) NOT NULL,
  `not_content_id` int(11) NOT NULL,
  `not_content` int(11) NOT NULL,
  `not_type` int(11) NOT NULL,
  `not_read` int(11) NOT NULL,
  `not_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Table structure for table `relationships`
--

CREATE TABLE IF NOT EXISTS `relationships` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user1` int(11) NOT NULL,
  `user2` int(11) NOT NULL,
  `status` int(11) NOT NULL,
  `time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Table structure for table `users`
--

CREATE TABLE IF NOT EXISTS `users` (
  `idu` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(32) NOT NULL,
  `password` varchar(256) NOT NULL,
  `email` varchar(256) NOT NULL,
  `first_name` varchar(32) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `last_name` varchar(32) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `verified` int(11) NOT NULL,
  `posts` text CHARACTER SET utf32 NOT NULL,
  `photos` text CHARACTER SET utf32 NOT NULL,
  `followers` text CHARACTER SET utf32 NOT NULL,
  UNIQUE KEY `id` (`idu`),
  UNIQUE KEY `idu` (`idu`)
  ) ENGINE=InnoDB  DEFAULT CHARSET=latin1;

Answer 1

尝试在正在运行删除的用户上创建索引，这可以加快查询速度

Answer 2

在我的测试中，multi_query是执行多个不同查询的最快方法。为什么你觉得它运行缓慢？相比什么？

无论如何，改进可能来自为您经常搜索的某些列添加索引：

relationships.users2
relationships.users1
notifications.not_from
notifications.not_to
users.idu

添加索引可以加快搜索速度，但至少有两个缺点：

使数据库耗费更多资源，这可能会影响您的服务器性能
使写作操作花费更长时间

我认为您当前的查询没有任何问题。真的要考虑你所看到的缓慢性能是来自数据库查询本身，还是来自PHP进程的其余部分。尝试使用查询测量脚本时间，然后跳过查询并进行另一次测量（您可以对查询结果进行硬编码）。它会让你知道缓慢是否可归因于其他东西。

无论哪种方式，基准。

PHP SQL查询慢吗？

PHP函数

表结构

2 个答案: