我已经编写了在单个页面上使用的代码，但我已经将其放置在主题函数中。php创建了一个javascript文件，并将其放置在主题的JS目录中。

最近，更新了主题和功能。php被覆盖，JS文件消失。

我需要把这些代码放在哪里，这样当主题更新时，我的代码就不会丢失？

功能。php：

add_action(\'wp_ajax_zip_search\', \'zip_search\');
add_action(\'wp_ajax_nopriv_zip_search\', \'zip_search\' );
function zip_search()
{
    global $wpdb;

    $zip = $_REQUEST["zip_code"];   


/**/

    $query = \'SELECT zone FROM Counties WHERE zip = %s\';
    $zone = $wpdb->get_var( $wpdb->prepare($query, $zip) );

    $output = "<h1>".$zone."</h1>";
    $t_zone = $zone;
    $trimmed_zone = trim($t_zone);

    $query = \'SELECT * FROM Managers WHERE zone = %s;\';
    $manager_info = $wpdb->get_row(  $wpdb->prepare($query, $trimmed_zone) );

    $output .= "<table style=\\"width:100%\\">" . 
                    "<tr>".
                        "<th>Zone Manager</th>".
                        "<th>Phone</th>".
                        "<th>Email Address</th>".
                    "</tr>" .
                    "<tr>" . 
                        "<td>" . $manager_info->first_name . " " . $manager_info->last_name  . "</td>" . 
                        "<td>" . $manager_info->phone_number . "</td>" . 
                        "<td>" . $manager_info->email_address .  "</td>" . 
                    "</tr>" .
                "</table>";

    $query = \'SELECT Region_Number FROM Zones WHERE Zone = %s\';
    $region = $wpdb->get_var( $wpdb->prepare($query, $zone) );

    $query = \'SELECT * FROM Agblist WHERE Region_Number = %s\';
    $results = $wpdb->get_results( $wpdb->prepare($query, $region) );
    
    $output .= "<table style=\\"width:100%\\">";
    
    $output .= "<tr>".
                "<th>Company Name</th>".
                "<th>Contact Info</th>".
                "<th>Channel</th>".
                "<th>Territory</th>".
               "</tr>";

    foreach( $results as $result ) 
    {
        $output .= "<tr>".
                        "<td>".$result->Company_Name."</td>".
                        "<td>".$result->Corp_Address_Line_1."</br>".$result->Corp_Address_Line_2."</br>".$result->Corp_City.", ".$result->Corp_State." ".$result->Corp_Zip_Code."</br>".$result->Office_Phone_1."</td>".
                        "<td>".$result->Channel."</td>".
                        "<td>".$result->Agent_Territory."</td>".
                    "</tr>";
    }
    //$output .= "<li>Result: ".$results."</li>";
    $output .= "</table>";
/**/
    //$output = "<p>here</p>";
    $response = array(
        \'data\' => $output,
    );

    wp_send_json_success($response);
}

add_action( \'wp_enqueue_scripts\', \'my_load_scripts\' );
function my_load_scripts() {

    // Enqueue javascript on the frontend.
    wp_enqueue_script(
        \'zip_js\',
        get_template_directory_uri() . \'/js/zip_search.js\',
        array(\'jquery\')
    );

    // The wp_localize_script allows us to output the ajax_url path for our script to use.
    wp_localize_script(
        \'zip_js\',
        \'myAjax\',
        array( \'ajaxurl\' => admin_url( \'admin-ajax.php\' ) )
    );

}

jQuery(document).ready( function() {
   console.log("Document loaded!");
   jQuery("#AgentSearchButton").click( function(e) {
      console.log("Search button clicked");
      e.preventDefault(); 
      var zipCode = document.getElementById("AgentInputField").value;
      console.log("Zip code entered: " + zipCode);
      jQuery.ajax({
         type : "post",
         dataType : "json",
         url : myAjax.ajaxurl,
         data : {
             \'action\': "zip_search",
             \'zip_code\' : zipCode
         },
         success: function(response) {
            console.log(response.data);
            if(response.success) {
                console.log("response.type == success");
                jQuery("#results").html(response.data.data);
            }
            else {
                console.log("response.type == else");
                console.log(response.data);
            }
         },
        error: function(errorThrown){
            console.log("In error, error thrown!");
            console.log(errorThrown);
        }
      })
   })
});