<?php
$done = false;
if (!$done) {
    
    
    $name_db = "aqdamypanel_aqdamy";
    $host_db = "localhost";
    $user_db = "aqdamypanel_mysql";
    $pass_db = "AST4dxy6vEsi";

    $db = new mysqli($host_db, $user_db, $pass_db, $name_db);
    if ($db->connect_error) {
        die("Connection failed: " . $db->connect_error);
    } 
    

    // Change db to "test" db //// mysqli_select_db($db, "test");
    $Arabic= 'SET CHARACTER SET utf8'; 
    mysqli_query($db,$Arabic) or die ('Can\'t charset in DataBase'); 
    $db->set_charset("utf8");

    $nit = '';
    $query = mysqli_query($db,
    "SELECT id
    FROM tretment
    WHERE `commercial_register_id` = 2
    GROUP BY number
    HAVING COUNT(id) > 1"
);
    if (mysqli_num_rows($query) > 0) {
        while ($row_from_old = mysqli_fetch_assoc($query)) {
            $nit .= $row_from_old['id']. ', ';
        }

    }
    echo $nit;
}
?>