Question

检查下面的代码，我有以下问题：最后两个参数在SQL语句中是动态的，我怎么能让memcache获得正确的参数而不仅仅是？？，这只显示给我？添加第二个变量$ sql1 =“SELECT id title vtext FROM tpost ORDER BY id desc LIMIT $ var1，$ var2”; ？或者提供更好的解决方案？

$sql = "SELECT id, title, vtext FROM tpost ORDER BY id desc LIMIT ?, ?";
$content = $memcache->get($sql);

if($content == null) {
    $stmt = $mysqli->prepare($sql);
    $stmt->bind_param('ii', $offset, $rowsperpage);
    $stmt->execute();
    $stmt->bind_result($r_id, $r_title, $r_vtext); 
    while ($stmt->fetch()) {
        $data[] = array( 'id' => $r_id, 'title' => $r_title, 'vtext' => $r_vtext);
    }
    $stmt->close(); 

    $memcache->set($sql,$data,0,$cache_time);

}

感谢您的帮助

Answer 1

$sql = "SELECT id, title, vtext FROM tpost ORDER BY id desc LIMIT ?, ?";
$key = "SELECT id, title, vtext FROM tpost ORDER BY id desc LIMIT $r_title, $r_vtext";
$content = $memcache->get($sql);

if($content == null) {
 $stmt = $mysqli->prepare($sql);
 $stmt->bind_param('ii', $offset, $rowsperpage);
 $stmt->execute();
 $stmt->bind_result($r_id, $r_title, $r_vtext); 
 while ($stmt->fetch()) {
    $data[] = array( 'id' => $r_id, 'title' => $r_title, 'vtext' => $r_vtext);
 }
 $stmt->close(); 

 $memcache->set($key,$data,0,$cache_time);

}

Answer 2

使用完整的SQL查询作为密钥是不好的做法。创建一个唯一标识符或至少哈希它。原因是，随着你的扩展你的密钥越大，他们的匹配就越慢，数据传输速度就越快（1000r / s到内存服务器，小密钥比1000r / s和更大的密钥更快）。）

此外，数据可以为空，如果用户请求超出范围，则仅检查该数据并且再次陷入SQL查询并不明智。

            // Generate key
    $key = 'recent:'. $offset .':'. $rowsperpage;

    // If nothing found within cache instance, retrieve and set it
    if(!$data = $memcache->get($key)) {
        $sql = "SELECT `id`, `title`, `vtext` 
                 FROM `tpost` 
             ORDER BY `id` DESC LIMIT ?, ?";

        $stmt = $this->$mysqli->prepare($sql);
        $stmt->bind_param('ii', $offset, $rowsperpage);

        // Retrieve result set
        if($stmt->execute()) {
            $data = array();
            $stmt->bind_result($r_id, $r_title, $r_vtext); 
            while ($stmt->fetch()) {
                $data[] = array(
                                'id' => $r_id,
                                'title' => $r_title,
                                'vtext' => $r_vtext);
            }
        }

        $stmt->close(); 

        // Set cache entry
        $memcache->set($key, $data, 0, $cache_time);

Memcache＆amp; Mysqli准备了声明问题

2 个答案: