Head First PHP&MySQL 学习笔记（三,四） —— 现实的实际应用
PHP
超级全局变量
_$SERVER['PHP_SELF']存储了当前脚本的名字。如，sendemail.php中_$SERVER['PHP_SELF']的值是'sendemail.php'
逻辑运算符
! || &&
判断语句if --- PHP的语法与C语言惊人的相似
if () //>, >=, <, <=, !=(<>), ==
{
;
}
else
{
;
}
foreach循环遍历
foreach($_POST['todelete'] as $delete_id) {
$query = "DELETE FROM email_list WHERE id='$delete_id'";
mysqli_query($dbc, $query) or die("Error querying database.");
//echo $query . '<br />';
}
表单中的数组 todelete[]
'[]' 告诉PHP脚本，$_POST[‘todelete’]是一个数组
while ($row = mysqli_fetch_array($result))
{
$firstname = $row['first_name'];
$lastname = $row['last_name'];
echo '<input type="checkbox" value="' . $row['id'] . '"name="todelete[]" />';
echo $row['first_name'];
echo ' ' . $row['last_name'];
echo ' ' . $row['email'];
echo '<br />';
}
PHP中可以这样
一个if...else语句段可以放在两个连续的<?php ?>中。也就是说PHP解析器连续的执行<?php ?>中的PHP脚本。
<?php
$output_form = false;
if($output_form)
{
?>
<!-- html content -->
<?php
}
else
{
//.....
}
?>
PHP自引用（删掉html只用php就够了）
PHP中同时包含HTML和PHP脚本,见文章最后面的示例程序
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label for="subject">Subject of email:</label><br />
<input id="subject" name="subject" type="text" size="30"
value="<?php echo $subject; ?>"/><br />
<label for="elvismail">Body of email:</label><br />
<textarea id="elvismail" name="elvismail" rows="8" cols="40"
><?php echo $text; ?></textarea><br />
<input type="submit" name="submit" value="Submit" />
</form>
MySQL
修改表属性ALTER TABLE
ALTER TABLE email_list ADD id INT NOT NULL AUTO_INCREMENT FIRST, ADD PRIMARY KEY(id);
示例程序
//sendemail.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>Make Me Elvis - Send Email</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<img src="blankface.jpg" width="161" height="350" alt="" style="float:right" />
<img name="elvislogo" src="elvislogo.gif" width="229" height="32" border="0" alt="Make Me Elvis" />
<p><strong>Private:</strong> For Elmer's use ONLY<br />
Write and send an email to mailing list members.</p>
<?php
$output_form = false;
if(isset($_POST['submit']))
{
$from = '[email protected]';
$subject = $_POST['subject'];
$text = $_POST['elvismail'];
if(empty($subject) || empty($text))
{
echo 'You forgot the email subject or content.<br />';
//echo $_POST['submit'] . '<br />';
$output_form = true;
}
}
else
{
$output_form = true;
}
if($output_form)
{
?>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label for="subject">Subject of email:</label><br />
<input id="subject" name="subject" type="text" size="30"
value="<?php echo $subject; ?>"/><br />
<label for="elvismail">Body of email:</label><br />
<textarea id="elvismail" name="elvismail" rows="8" cols="40"
><?php echo $text; ?></textarea><br />
<input type="submit" name="submit" value="Submit" />
</form>
<?php
}
else
{
$dbc = mysqli_connect('localhost', 'root', '123456', 'elvis_store')
or die('Error connecting to MySQL server.');
$query = "SELECT* FROM email_list";
$result = mysqli_query($dbc, $query) or die("Error querying database.");
while ($row = mysqli_fetch_array($result))
{
$firstname = $row['first_name'];
$lastname = $row['last_name'];
$msg = "Dear $firstname $lastname,\n$text";
$to = $row['email'];
//mail($to, $subject, $msg, 'From:' . $from); /* Note: sendmail need installed the configured correctly */
echo 'Email sent to:' . $to . '<br />';
}
mysqli_close($dbc);
//echo "Customer added:\n $firstname, \n $lastname, \n $emal"
}
?>
</body>
</html>
//removeemail.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>Make Me Elvis - Remove Email</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<img src="blankface.jpg" width="161" height="350" alt="" style="float:right" />
<img name="elvislogo" src="elvislogo.gif" width="229" height="32" border="0" alt="Make Me Elvis" />
<?php
$dbc = mysqli_connect('localhost', 'root', '123456', 'elvis_store')
or die('Error connecting to MySQL server.');
if(isset($_POST['Remove'])) {
foreach($_POST['todelete'] as $delete_id) {
$query = "DELETE FROM email_list WHERE id='$delete_id'";
mysqli_query($dbc, $query) or die("Error querying database.");
//echo $query . '<br />';
}
}
?>
<p>Select the customers you want to remove.</p>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'] ?>">
<label for="email">Customers:</label><br />
<?php
$query = "SELECT* FROM email_list";
$result = mysqli_query($dbc, $query) or die("Error querying database.");
while ($row = mysqli_fetch_array($result))
{
$firstname = $row['first_name'];
$lastname = $row['last_name'];
echo '<input type="checkbox" value="' . $row['id'] . '"name="todelete[]" />';
echo $row['first_name'];
echo ' ' . $row['last_name'];
echo ' ' . $row['email'];
echo '<br />';
}
mysqli_close($dbc);
?>
<input type="submit" name="Remove" value="Remove" />
</form>
</body>
</html>