如何使用AJAX调用PHP函数？

Question

I'm running my server on localhost using XAMPP, and I want to call a Javascript function which sends some data from the browser to a php script

The JS function is called when the a button on my html page is pressed:

function send_verification_code(){
    var xhttp = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject('Microsoft.XMLHTTP');
    xhttp.open('GET','database.php?email='+email_address)
    xhttp.send()
}

So I want to add, to the $_GET array, a key-value pair of email=>email_address, where email_address is a string, in the function above.

Immediately after the function above executes, I want to call another function, a PHP function which adds that data to a SQL database on my server by calling add_email_to_be_verified (the function belongs to the php script im sending the data to):

database.php:

<?php
     $dbhost = "localhost";
     $dbuser = "root";
     $dbpass = "";
     $db = "example";
     $conn;

     function add_email_to_be_verified(){
        connect();
         $sql = 'insert into emailstobeverified values(';
         $sql .= $_GET['email'];
         $sql .= ',';
         $sql .= generate_verification_code();
         $sql .= ',';
         $sql .= date("Y-m-d H:i:s");
         $sql .= ');';
         query($sql);
         disconnect();

     }
     function generate_verification_code(){ //generates a random 6-digit verification code
        $code = mt_rand(0,999999);
        $padded_code = sprintf('%06d', $code);
        return $padded_code;
     }
     function connect(){
        $conn = new mysqli($dbhost, $dbuser, $dbpass,$db) or die("Connect failed: %s
". $conn -> error);
     }
     function query(sql){
        $conn->query($sql);
     }
     function disconnect(){
        $conn -> close();
     }
?>

How can I call the php function using AJAX?

Answer 1

You can call the function when the get emaiAddress is detected on your database.php page. For example:

if(isset($_GET['email'])){
    add_email_to_be_verified($_GET['email']);
}

I would also modify your function to take the email in as a parameter, but you could also have that function find the email from the get as well.

Here's and example of the function with the email parameter:

function add_email_to_be_verified($email){

     connect();
     $sql = 'insert into emailstobeverified values(';
     $sql .= $email;
     $sql .= ',';
     $sql .= generate_verification_code();
     $sql .= ',';
     $sql .= date("Y-m-d H:i:s");
     $sql .= ');';
     query($sql);
     disconnect();
}