我正在制作一个注册/登录脚本，如果未设置$ _POST，将首先显示注册表单。如果是，但是未填写必填字段，则会再次重定向到该页面，重新设置$ _POST。如果填写了所有字段，则如果设置了提交按钮$ _POST [“login”]的名称，则表单确认登录并设置一个文本块，该页面是将用户重定向到他们的购物篮或回到商店。如果设置了提交按钮$ _POST [“register”]，则用户想要注册并构建并提交插入查询。如果此查询未返回受影响的行，则脚本将检查用户是否已注册。如果是这样，请将其登录并按正常登录方式向他们显示重定向页面。否则，如果脚本返回1行受影响，那么我假设插入成功（如果查询失败，我有脚本中断）。
如果您登录时登录有效，如果您错过了必填字段，则重定向会起作用，但就是这样。我看不出问题而且没有错误 - 在其他情况下我只是得到一个空白屏幕。这是一大堆代码，我害怕......
<?php
if(!$_POST) {
//hasn't seen the registration form
//display registration form
$display_block = "
<form method=\"POST\" action=\"".$_SERVER["PHP_SELF"]."\">
<p>Please fill in the registration field (required fields marked with <span class=\"req\"><</span>)<br />
First name: <input type=\"text\" name=\"f_name\" size=\"25\" maxlength=\"50\" /><span class=\"req\"><</span><br />
Last name: <input type=\"text\" name=\"l_name\" size=\"25\" maxlength=\"50\" /><span class=\"req\"><</span><br />
Address: <input type=\"text\" name=\"address\" size=\"50\" maxlength=\"150\" /><br />
Town: <input type=\"text\" name=\"town\" size=\"50\" maxlength=\"150\" /><br />
City: <input type=\"text\" name=\"city\" size=\"50\" maxlength=\"150\" /><br />
Post Code: <input type=\"text\" name=\"postcode\" size=\"10\" maxlength=\"10\" /><br />
Username: <input type=\"text\" name=\"username\" size=\"25\" maxlength=\"25\" /><span class=\"req\"><</span><br />
Confirm username: <input type=\"text\" name=\"usernameConfirm\" size=\"25\" maxlength=\"25\" /><span class=\"req\"><</span><br />
Password: <input type=\"password\" name=\"password\" size=\"25\" maxlength=\"25\" /><span class=\"req\"><</span><br />
Confirm password: <input type=\"password\" name=\"passwordConfirm\" size=\"25\" maxlength=\"25\" /><span class=\"req\"><</span><br />
<br />
<input type=\"submit\" name=\"register\" value=\"Register\" /><br /><br />
Already a member? <input type=\"submit\" name=\"login\" value=\"Login\" />
</p>";
} else if ((!isset($_POST["username"])) || (!isset($_POST["usernameConfirm"])) || (!isset($_POST["password"])) || (!isset($_POST["passwordConfirm"]))) {
//hasn't filled out all the fields
header("Location: ".$_SERVER["PHP_SELF"]."");
exit;
} else if($_POST["login"]) {
//user is logging in, so connect to server and select database, check they are registered and their details are right
$mysqli = mysqli_connect(hostname,username,pass,dbname);
//create and issue the query
$sql = "SELECT f_name, l_name FROM auth_users WHERE username='".$_POST["username"]."' AND password=PASSWORD('".$_POST["password"]."')";
$sql_res =mysqli_query($mysqli, $sql) or die(mysqli_error($mysqli));
//get the number of rows in the result set; should be 1 if a match
if(mysqli_num_rows($sql_res) == 1) {
//if authorized, get the values of f_name, l_name
while($info = mysqli_fetch_array($sql_res)) {
$f_name = stripslashes($info["f_name"]);
$l_name = stripslashes($info["l_name"]);
}
//set authorization cookie
setcookie("auth", "1", 0, "/", "sinaesthesia.co.uk", 0);
//create display string
$display_block = "<p>".$f_name." ".$l_name." is authorized.</p>
<p>You are now logged in.</p>
<a href=\"basket.php5\">View Basket</a> | <a href=\"home.php5\">Continue Shopping</a>";
} else if($_POST["register"]) {
//connect to db and issue registration query
$mysqli = mysqli_connect(hostname,username,pass,dbname);
$register_sql = "INSERT INTO aromaMaster (username, password, date_registered) VALUES ('".$_POST["username"]."',PASSWORD('".$_POST["password"]."'),now())";
$register_res = mysqli_query($mysqli, $register_sql) or die(mysqli_error($mysqli));
if (mysqli_num_rows($register_res) != 1) {
//registration failed - perhaps duplicate account
$check_sql = "SELECT username, password FROM aromaMaster WHERE username='".$_POST["username"]."' AND password=PASSWORD('".$_POST["password"]."')";
$check_res = mysqli_query($mysqli, $check_sql) or die(mysqli_error($mysqli));
if(mysqli_num_rows($check_res) == 1) {
//already a member
//set cookie
//set authorization cookie
setcookie("auth", "1", 0, "/", "sinaesthesia.co.uk", 0);
$display_block = "
<p>You are already registered.</p>
<a href=\"basket.php5\">View Basket</a> | <a href=\"home.php5\">Continue Shopping</a>";
}
} else {
//success
$display_block = "
<p>You are registered!</p>
<a href=\"basket.php5\">View Basket</a> | <a href=\"home.php5\">Continue Shopping</a>";
}
}
mysqli_close($mysqli);
}
?>
<html>
<head>
<title>Login / Register</title>
</head>
<body>
<?php echo "$display_block"; ?>
</body>
</html>