我在为我的网站制作新系统时遇到问题。我正在开发一个新的connect.php和approved.php（用于其他方式） 我似乎无法让它发挥作用。这是approved.php
approved.php
<?php
include_once "connect.php";
include_once "strings.php";
connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][0]);
//echo $newConn;
mysqli_query($newConn, "SELECT * FROM `loginsystem`") or die("Could not connect");
?>
这是 connect.php
<?php
function connect($servername, $username, $password, $dbname)
{
include "strings.php";
if ($servername == $conn[0][0] && $username == $conn[1][0] && $password == $conn[2][0] && $dbname == $conn[3][0] ||
$servername == $conn[0][0] && $username == $conn[1][1] && $password == $conn[2][1] && $dbname == $conn[3][0] ||
$servername == $conn[0][0] && $username == $conn[1][2] && $password == $conn[2][2] && $dbname == $conn[3][0])
{
$newConn;
if ($newConn = mysqli_connect($conn[0][0], $conn[1][0], $conn[2][0], $conn[3][0])
|| $newConn = mysqli_connect($conn[0][0], $conn[1][1], $conn[2][1], $conn[3][0])
|| $newConn = mysqli_connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][0]))
{
echo $processMsg;
}
else
{
echo $errorMsg;
die();
}
return $newConn;
}
else if ($servername == $conn[0][0] && $username == $conn[1][0] && $password == $conn[2][0] && $dbname == $conn[3][1] ||
$servername == $conn[0][0] && $username == $conn[1][1] && $password == $conn[2][1] && $dbname == $conn[3][1] ||
$servername == $conn[0][0] && $username == $conn[1][2] && $password == $conn[2][2] && $dbname == $conn[3][1])
{
if ($newConn = mysqli_connect($conn[0][0], $conn[1][0], $conn[2][0], $conn[3][1])
|| $newConn = mysqli_connect($conn[0][0], $conn[1][1], $conn[2][1], $conn[3][1])
|| $newConn = mysqli_connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][1]))
{
echo $processMsg;
}
else
{
echo $errorMsg;
die();
}
return $newConn;
}
else
{
die("Something went wrong with our systems");
}
}
?>
最后 strings.php 取出敏感信息
<?php
//Information taken out for stack overflow question - not everything is here
include_once("connect.php");
$tablesChromeAds = ["food", "software", "hardware", "home", "outdoor", "indooract", "services", "other"];
$conn = array(array($server) /*both our servers go under localhost*/, array($admin, $admin1, $localAdmin), array($adminPass, $admin1Pass, $localAdminPass), array($dbGeneralDB, $dbBrowserExtensions));
$newConn;
$errorMsg = "<script type='text/javascript'>Notification.requestPermission().then(function(result) {console.log(result);});var notification = new Notification('Smart Lead Advertisement Error', {icon: '$logo',body: 'Cannot connect to database'});</script>";
$processMsg = "<script type='text/javascript'>Notification.requestPermission().then(function(e) {console.log(e);});var notification = new Notification('Smart Lead Advertisement', {icon: '$logo',body: 'Processing request...'});</script>";
//Get the value for the presale license's from the mysql database to be stored within a variable which can be later accessed from any file
$num = 50;
?>
现在我知道的所有内容都包含正确。在我尝试连接之前没有错误发生。我没有这个 之前的问题。错误如下所示
Notice: Undefined variable: newConn in C:\xampp\htdocs\smartlead\php\approved.php on line 6
Notice: Undefined variable: newConn in C:\xampp\htdocs\smartlead\php\approved.php on line 8
Warning: mysqli_query() expects parameter 1 to be mysqli, null given in C:\xampp\htdocs\smartlead\php\approved.php on line 8
所以我知道newConn变量未正确返回的一件事。但为什么？我该如何解决这个问题？
答案 0 :(得分：2)
由 u_mulder
评论$newConn = connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][0]);
//echo $newConn;
mysqli_query($newConn, "SELECT * FROM `loginsystem`") or die("Could not connect");
如果您的connection未成立，请尝试使用echo mysqli_connect_error();函数
connect.php
<?php
function connect($servername, $username, $password, $dbname) {
include "strings.php";
if ($servername == $conn[0][0] && $username == $conn[1][0] && $password == $conn[2][0] && $dbname == $conn[3][0] ||
$servername == $conn[0][0] && $username == $conn[1][1] && $password == $conn[2][1] && $dbname == $conn[3][0] ||
$servername == $conn[0][0] && $username == $conn[1][2] && $password == $conn[2][2] && $dbname == $conn[3][0]) {
$newConn;
if ($newConn = mysqli_connect($conn[0][0], $conn[1][0], $conn[2][0], $conn[3][0]) || $newConn = mysqli_connect($conn[0][0], $conn[1][1], $conn[2][1], $conn[3][0]) || $newConn = mysqli_connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][0])) {
echo $processMsg;
} else {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
echo $errorMsg;
die();
}
return $newConn;
} else if ($servername == $conn[0][0] && $username == $conn[1][0] && $password == $conn[2][0] && $dbname == $conn[3][1] ||
$servername == $conn[0][0] && $username == $conn[1][1] && $password == $conn[2][1] && $dbname == $conn[3][1] ||
$servername == $conn[0][0] && $username == $conn[1][2] && $password == $conn[2][2] && $dbname == $conn[3][1]) {
if ($newConn = mysqli_connect($conn[0][0], $conn[1][0], $conn[2][0], $conn[3][1]) || $newConn = mysqli_connect($conn[0][0], $conn[1][1], $conn[2][1], $conn[3][1]) || $newConn = mysqli_connect($conn[0][0], $conn[1][2], $conn[2][2], $conn[3][1])) {
echo $processMsg;
} else {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
echo $errorMsg;
die();
}
return $newConn;
} else {
die("Something went wrong with our systems");
}
}
?>
答案 1 :(得分：1)
以下是一个函数赋值如何在PHP中工作的示例。
function test() {
$moose = 'Wow';
return $moose;
}
test();
echo 'empty->' . $moose . "<-empty"; //undefined;
$moose = test();
echo $moose;
关于第一个函数调用test()的注意事项我们对返回的值没有任何作用，所以它只是丢失了。所有变量也与其功能相关。您可以在函数中调用变量$cattle，然后在脚本中调用$moose，并且所有$moose引用都可以。