Head First PHP&mysql学习笔记(四)
五. 使用存储在文件中的数据
1. "@"：PHP错误抑制指令，该表达式可能产生的任何错误信息都被忽略掉。
2. $_FILES内置超级全局变量允许访问上传文件的有关信息
$_FILES[‘file’][‘name’]：上传文件的文件名 $_FILES[‘file’][‘type’]：上传文件的MIME类型
$_FILES[‘file’][‘size’]：上传文件的大小 $_FILES[‘file’][‘tmp_name’]：文件在服务器上的临时存储位置
$_FILES[‘file’][‘error’]：文件上传的错误码，0表示成功，其他值表示失败
3. 存储在外部文件中的数据一般就留在外部文件中，即使是数据库应用也往往如此
4. 在Web页面上放置一个图像只需要该图像文件的一个引用
5. move_uploaded_file($_FILES[‘screenshot’][‘tmp_name’],$target) 接受一个文件的源位置和目标位置，完成文件移动
6. 共享的脚本数据需要在整个应用中都能访问，而无需代码重复；包含文件允许在多个脚本之间共享代码
7. GET和POST这两种Web请求控制着脚本之间如何传递数据：
POST：用于向服务器发送数据，从而以某种方式导致服务器上状态的改变，如在数据库中插入数据。数据还可以在响应中返回。不同于GET，POST请求只能通过Web表单的动作完成。另外与GET不同，POST请求中发送的数据是隐藏不可见的。
GET：一般用于数据获取，而不会使服务器有任何改变。对于少量的数据，GET非常有用，可以直接在URL中向服务器发送数据。与POST不同，GET主要适用于发送少量的数据。
8. GET&POST应用代码实例：
<!-- addvars.php --> <?php // Define application constants define('GW_UPLOADPATH', 'images/'); // 将图片文件Move到images文件夹下 define('GW_MAXFILESIZE', 32768); // 32 KB ?>
<!-- connectvars.php --> <?php // Define database connection constants define('DB_HOST', 'localhost'); define('DB_USER', 'root'); define('DB_PASSWORD', ''); define('DB_NAME', 'gwdb'); ?>
<!-- addscore.php --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Guitar Wars - Add Your High Score</title> <link rel="stylesheet" type="text/css" href="style.css" /> </head> <body> <h2>Guitar Wars - Add Your High Score</h2> <?php require_once('appvars.php'); // require_once()函数，未找到appvars.php会报错 require_once('connectvars.php'); if (isset($_POST['submit'])) { // Grab the score data from the POST $name = $_POST['name']; $score = $_POST['score']; $screenshot = $_FILES['screenshot']['name']; $screenshot_type = $_FILES['screenshot']['type']; $screenshot_size = $_FILES['screenshot']['size']; if (!empty($name) && !empty($score) && !empty($screenshot)) { if ((($screenshot_type == 'image/gif') || ($screenshot_type == 'image/jpeg') || ($screenshot_type == 'image/pjpeg') || ($screenshot_type == 'image/png')) && ($screenshot_size > 0) && ($screenshot_size <= GW_MAXFILESIZE)) { if ($_FILES['screenshot']['error'] == 0) { // Move the file to the target upload folder $target = GW_UPLOADPATH . $screenshot; if (move_uploaded_file($_FILES['screenshot']['tmp_name'], $target)) { // 将上传图片从临时位置转移到images文件夹下 // Connect to the database $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME); // Write the data to the database $query = "INSERT INTO guitarwars VALUES (0, NOW(), '$name', '$score', '$screenshot')"; // NOW()函数用于插入当前日期/时间 mysqli_query($dbc, $query); // Confirm success with the user echo '<p>Thanks for adding your new high score! It will be reviewed and added to the high score list as soon as possible.</p>'; echo '<p><strong>Name:</strong> ' . $name . '<br />'; echo '<strong>Score:</strong> ' . $score . '<br />'; echo '<img src="' . GW_UPLOADPATH . $screenshot . '" alt="Score image" /></p>'; echo '<p><a href="index.php"><< Back to high scores</a></p>'; // Clear the score data to clear the form $name = ""; $score = ""; $screenshot = ""; mysqli_close($dbc); } else { echo '<p class="error">Sorry, there was a problem uploading your screen shot image.</p>'; } } } else { echo '<p class="error">The screen shot must be a GIF, JPEG, or PNG image file no greater than ' . (GW_MAXFILESIZE / 1024) . ' KB in size.</p>'; } // Try to delete the temporary screen shot image file @unlink($_FILES['screenshot']['tmp_name']); // unlink()函数从Web服务器删除一个文件，用@以防在文件上传未成功时显示错误报告 } else { echo '<p class="error">Please enter all of the information to add your high score.</p>'; } } ?> <hr /> <form enctype="multipart/form-data" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> <input type="hidden" name="MAX_FILE_SIZE" value="<?php echo GW_MAXFILESIZE; ?>" /> <label for="name">Name:</label> <input type="text" id="name" name="name" value="<?php if (!empty($name)) echo $name; ?>" /><br /> <label for="score">Score:</label> <input type="text" id="score" name="score" value="<?php if (!empty($score)) echo $score; ?>" /><br /> <label for="screenshot">Screen shot:</label> <input type="file" id="screenshot" name="screenshot" /> <hr /> <input type="submit" value="Add" name="submit" /> </form> </body> </html>
<!-- admin.php --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Guitar Wars - High Scores Administration</title> <link rel="stylesheet" type="text/css" href="style.css" /> </head> <body> <h2>Guitar Wars - High Scores Administration</h2> <p>Below is a list of all Guitar Wars high scores. Use this page to remove scores as needed.</p> <hr /> <?php require_once('appvars.php'); require_once('connectvars.php'); // Connect to the database $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME); // Retrieve the score data from MySQL $query = "SELECT * FROM guitarwars ORDER BY score DESC, date ASC"; // 回忆ORDER BY,DESC,ASC排序用法 $data = mysqli_query($dbc, $query); // Loop through the array of score data, formatting it as HTML echo '<table>'; while ($row = mysqli_fetch_array($data)) { // Display the score data echo '<tr class="scorerow"><td><strong>' . $row['name'] . '</strong></td>'; echo '<td>' . $row['date'] . '</td>'; echo '<td>' . $row['score'] . '</td>'; echo '<td><a href="removescore.php?id=' . $row['id'] . '&date=' . $row['date'] . // & = & '&name=' . $row['name'] . '&score=' . $row['score'] . '&screenshot=' . $row['screenshot'] . '">Remove</a></td></tr>'; } echo '</table>'; mysqli_close($dbc); // 不要忘记mysqli_close()操作 ?> </body> </html>
<!-- index.php --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Guitar Wars - High Scores</title> <link rel="stylesheet" type="text/css" href="style.css" /> </head> <body> <h2>Guitar Wars - High Scores</h2> <p>Welcome, Guitar Warrior, do you have what it takes to crack the high score list? If so, just <a href="addscore.php">add your own score</a>.</p> <hr /> <?php require_once('appvars.php'); require_once('connectvars.php'); // Connect to the database $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME); // Retrieve the score data from MySQL $query = "SELECT * FROM guitarwars ORDER BY score DESC, date ASC"; $data = mysqli_query($dbc, $query); // Loop through the array of score data, formatting it as HTML echo '<table>'; $i = 0; while ($row = mysqli_fetch_array($data)) { // Display the score data if ($i == 0) { // 找到排序好的数据库中第一个，为最高分添加css样式 echo '<tr><td colspan="2" class="topscoreheader">Top Score: ' . $row['score'] . '</td></tr>'; } echo '<tr><td class="scoreinfo">'; echo '<span class="score">' . $row['score'] . '</span><br />'; echo '<strong>Name:</strong> ' . $row['name'] . '<br />'; echo '<strong>Date:</strong> ' . $row['date'] . '</td>'; // is_file函数查看该文件是否存在,filesize()函数检查并确保上传文件不为空 if (is_file(GW_UPLOADPATH . $row['screenshot']) && filesize(GW_UPLOADPATH . $row['screenshot']) > 0) { echo '<td><img src="' . GW_UPLOADPATH . $row['screenshot'] . '" alt="Score image" /></td></tr>'; } else { echo '<td><img src="' . GW_UPLOADPATH . 'unverified.gif' . '" alt="Unverified score" /></td></tr>'; } $i++; } echo '</table>'; mysqli_close($dbc); ?> </body> </html>
<!-- removescore.php --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Guitar Wars - Remove a High Score</title> <link rel="stylesheet" type="text/css" href="style.css" /> </head> <body> <h2>Guitar Wars - Remove a High Score</h2> <?php require_once('appvars.php'); require_once('connectvars.php'); if (isset($_GET['id']) && isset($_GET['date']) && isset($_GET['name']) && isset($_GET['score']) && isset($_GET['screenshot'])) { // Grab the score data from the GET $id = $_GET['id']; // 使用GET方法得到admin.php传来的数据 $date = $_GET['date']; $name = $_GET['name']; $score = $_GET['score']; $screenshot = $_GET['screenshot']; } else if (isset($_POST['id']) && isset($_POST['name']) && isset($_POST['score'])) { // Grab the score data from the POST $id = $_POST['id']; // 使用POST方法得到自引用的数据 $name = $_POST['name']; $score = $_POST['score']; } else { echo '<p class="error">Sorry, no high score was specified for removal.</p>'; } if (isset($_POST['submit'])) { if ($_POST['confirm'] == 'Yes') { // Delete the screen shot image file from the server @unlink(GW_UPLOADPATH . $screenshot); // 避免显示错误，尤其适用于unlink() // Connect to the database $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME); // Delete the score data from the database $query = "DELETE FROM guitarwars WHERE id = $id LIMIT 1"; // LIMIT 1限制最多删除一条 mysqli_query($dbc, $query); mysqli_close($dbc); // Confirm success with the user echo '<p>The high score of ' . $score . ' for ' . $name . ' was successfully removed.'; } else { echo '<p class="error">The high score was not removed.</p>'; } } else if (isset($id) && isset($name) && isset($date) && isset($score)) { echo '<p>Are you sure you want to delete the following high score?</p>'; echo '<p><strong>Name: </strong>' . $name . '<br /><strong>Date: </strong>' . $date . '<br /><strong>Score: </strong>' . $score . '</p>'; echo '<form method="post" action="removescore.php">'; // 没有使用$_SERVER['PHP_SELF'],因为它会包含作为GET通过URL查询串传递的所有数据 echo '<input type="radio" name="confirm" value="Yes" /> Yes '; echo '<input type="radio" name="confirm" value="No" checked="checked" /> No <br />'; echo '<input type="submit" value="Submit" name="submit" />'; echo '<input type="hidden" name="id" value="' . $id . '" />'; // 使用隐藏的表单域存储数据，使之能够作为POST请求的一部分发送 echo '<input type="hidden" name="name" value="' . $name . '" />'; echo '<input type="hidden" name="score" value="' . $score . '" />'; echo '</form>'; } echo '<p><a href="admin.php"><< Back to admin page</a></p>'; // 提供一个指回Admin页面的链接来改善导航 ?> </body> </html>
/* style.css */ .error { font-weight: bold; color: #FF0000; } .topscoreheader { text-align: center; font-size: 200%; background-color: #36407F; color: #FFFFFF; } .score { font-size:150%; color: #36407F; } .scoreinfo { vertical-align: top; padding-right:15px; }
欢迎大家阅读《Head First PHP&MySQL学习笔记(4)_mysql》,跪求各位点评，by 搞代码
搞代码网（gaodaima.com）提供的所有资源部分来自互联网，如果有侵犯您的版权或其他权益，请说明详细缘由并提供版权或权益证明然后发送到邮箱[email protected]，我们会在看到邮件的第一时间内为您处理，或直接联系QQ：872152909。本网站采用BY-NC-SA协议进行授权
转载请注明原文链接：Head First PHP&MySQL学习笔记(4)_mysql
转载请注明原文链接：Head First PHP&MySQL学习笔记(4)_mysql
