Question

我正在使用uploadify将图片上传到服务器。在后台，我使用的是PHP脚本。在PHP脚本中，除了复制到目标位置之外，我还在数据库中插入文件位置和其他一些细节。

问题：-如果我上传20个文件，PHP脚本会被调用20次，数据库插入语句会被调用二十次，以插入不同的图像。毫无疑问，调用数据库20次是一种效率低下的方法。有没有什么方法可以保存文件名（和位置），并只调用insert语句一次（最后），一次插入所有20条记录？

谢谢你的帮助

当做

基兰

Answer 1

为此，我推荐的一种方法是通过mysqli扩展使用准备好的语句。引用主要优点：

The actual purpose to use a prepared statement in sql is to cut the cost of processing queries; NOT to separate data from query. That s how it s being used w/ php NOW, not how it was designed to be used in the first place. With SQL you cut the cost of executing multiple similar queries down by using a prepared statement.. Doing so cuts out the parsing, validation and most often generates an execution plan for said query up front. Which is why they run faster in a loop, than their IMMEDIATE Query cousins do.

来源：http://us2.php.net/manual/en/mysqli.prepare.php#103730

举例说明如何利用此功能：

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s
", mysqli_connect_error());
    exit();
}

if ($stmt = $mysqli->prepare("INSERT INTO `images` (`location`, `size`, `othervalues`) VALUES(?, ?, ?)")) {
  foreach($images as $image) {
    // s = string value
    // i = integer value
    $stmt->bind_param("sis", $image[ location ], $image[ size ], $image[ othervalues ]);
    $stmt->execute();
  }
  $stmt->close();
}
// Your prepared statement failed, handle the error
else {
}

$mysqli->close();

我建议阅读mysqli:：准备和mysqli_stmt:：bind_param了解有关流程如何工作的详细信息。我还建议阅读在MySQL文档中准备了语句。

友情链接