How to use ajax to update label from count from mysql database - php

Question

I know ajax is probably the best method to do this.
So, i have this php file which returns a count:
<?php
include('globals.php');
$query = mysqli_query($con, "SELECT COUNT(*) as total FROM solicitacoes WHERE visualizada = 0");
$resultado = mysqli_fetch_array ($query);
$sem_visualizar = $resultado['total'];
return $sem_visualizar;
And i have this on my main page:
<?php
if($_SESSION['funcao_corrente']=="adm" || $_SESSION['funcao_corrente']=="analista"){
echo '<label onclick="mudaIframe();" id="visu" ';
if ($sem_visualizar == 0)
echo 'style="background-color: darkgray; color: black;"';
else if ($sem_visualizar<=5)
echo 'style="background-color: green;"';
else if ($sem_visualizar>5 && $sem_visualizar <= 15)
echo 'style="background-color: orangered;"';
else if ($sem_visualizar>15)
echo 'style="background-color: red;"';
echo '>'.$sem_visualizar.'</label>';
}
?>
Basically it just changes color based on value, but the thing is:
I want it to auto refresh it's own value via the PHP file which returns count, but I have absolutely no idea how can i do this.
I found this code in another answer, but it's not working.
<script>
function get_msg_count(){
$.ajax ({
data: {}, // not really needed
type: 'POST',
url: 'contar_sem_visualizar.php', // page to return your msg count
success: function(response)
{
$('#visu').html(response);
}
}
}); // End $.ajax
} // End Function
// and on DOM ready
$(function(){
// check for new messages every 3 seconds(3000ms)
setInterval(get_msg_count(), 3000)
});
</script>

Answer 1

You can just use $.load to achieve that:
HTML
<span id="count"></span>
jQuery
$("#count").load("contar_sem_visualizar.php");

Answer 2

You need an element to set the count and use jQuery to put the answer in there. The return from your PHP will be retrieved from the jQuery request and ever after a set interval the client's browser will send a request asking for this value, which will be added again to the counter.
You could do that:
function get_count(){
while()
{
$("#counter").load("contar_sem_visualizar.php");
setInterval(3000);
}
}
get_count();