ajax如何连接数据库（ajax请求本地数据库）

<button id="button2">多个用户</button>

<br>

<hr>

<h1>多个用户</h1>

<div id="users"></div>

<script>

document.getElementById('button2').addEventListener("click",loadUsers);

function loadUsers(){

var xhr=new XMLHttpRequest();

xhr.open('GET',"user.php",true);

xhr.onload=function(){

if(this.status==200){

var users=JSON.parse(this.responseText);

console.log(users);

var output='';

//遍历数据

for( var i in users){

output =`

<ul>

<li>${users[i].id}</li>

<li>${users[i].name}</li>

</ul>

`;

}

document.getElementById('users').innerHTML=output;

}

}

xhr.send();

}

</script>

user.php文件内容：

<?php

#链接数据库

$conn=mysqli_connect("localhost","root","root","ajaxtext");

$query='select * from users';

$result=mysqli_query($conn,$query);

$users=mysqli_fetch_all($result,MYSQLI_ASSOC);

echo json_encode($users);

?>