Mysqli PHP连接致命错误

Question

I am trying to create a connection from a web form to MySQL database using PHP. My code is as follows:

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();

This part seems to work.. It then connects to thank 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);

?>

I am getting the following errors:

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

There are several issues with your script:

1: You need to return the connection likes o:

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

2: When you run

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

You have already executed the SQL to the DB, you do not need $success = $conn->query($query);

So your code should be:

<?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);

?>