Mysqli PHP连接致命错误

Question

我想创建一个从Web表单到使用PHP的MySQL数据库的连接。我的代码如下：

connection.php：

<?php 
$link = mysqli_connect("", "", "", ""); 

if (!$link) { 
echo "Error: Unable to connect to MySQL." . PHP_EOL; 
echo "Debugging errno: " . mysqli_connect_errno() . PHP_EOL; 
echo "Debugging error: " . mysqli_connect_error() . PHP_EOL; 
exit; 
} 

echo "Success: A proper connection to MySQL was made! The my_db database is great." . PHP_EOL; 
echo "Host information: " . mysqli_get_host_info($link) . PHP_EOL; 

phpinfo(); 

这部分似乎工作..然后它连接到感谢you.php：

<?php 

function connect() 
    { 
     $conn = mysqli_connect("", "", "", ""); 
    } 

ini_set('display_errors', 1); error_reporting(~0); 

require 'connection.php'; 
$conn = Connect(); 
$query = mysqli_query($conn,"INSERT into Members (Username) VALUES('1111Username')"); 
$success = $conn->query($query); 

if (!$success) { 
die("Couldn't enter data: ".$conn->error); 

} 

echo "Thank You For Contacting Us <br>"; 

mysqli_close($conn); 

?> 

我收到以下错误：

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in /var/sites/i/site/public_html/ContactForm/thankyou.php on line 15

Fatal error: Call to a member function query() on null in /var/sites/i/site/public_html/ContactForm/thankyou.php on line 16

Answer 1

有几个问题与你的脚本：

1：你需要返回的连接喜欢○：

function connect() 
{ 
    return mysqli_connect("", "", "", ""); 
} 

2：当您运行

$query = mysqli_query($conn,"INSERT into Members (Username) VALUES('1821Username')"); 

您已经执行的SQL的数据库，你不需要$success = $conn->query($query);

所以，你的代码应该是：

<?php 

function connect() 
    { 
     return mysqli_connect("", "", "", ""); 
    } 

ini_set('display_errors', 1); error_reporting(~0); 

require 'connection.php'; 
$conn = connect(); 
$query = mysqli_query($conn,"INSERT into Members (Username) VALUES('1821Username')"); 

if (!$query) { 
die("Couldn't enter data: ".$conn->error); 

} 

echo "Thank You For Contacting Us <br>"; 

mysqli_close($conn); 

?>