Database Query - Order by two values (Nested Order) - mysql

Question

I want to order results by two database values: rating_full followed by rating_count
Currently, Im ordering by the highest rating_full. it works fine.
$sql .= " LEFT JOIN {$wpdb->postmeta} rating ON ({$wpdb->posts}.ID = rating.post_id AND rating.meta_key IN ('rating_full'))";
…
…
$sql = "cast(rating.meta_value as decimal(10,2)) {$order}";
……
The first line of code, part of the SELECT statement, retrieves the rating_full part
The second line of code is the ORDER BY part, which currently just uses the rating_count
As far as I can tell rating.meta_value referred to in the second line of code is the rating_full value
I'm trying to get it to ORDER BY rating_full, rating_count
I'm not sure how to modify the first line so that I can achieve this.
Thanks
FULL CODE:
<?php
// Sorting
add_filter('posts_join', 'directorySortingJoin',10,2);
function directorySortingJoin($join, $query) {
global $wpdb, $aThemeOptions;
if ($query->is_main_query() && !$query->is_admin && ((isset($_GET['dir-search'])) || (isset($query->query_vars["a-dir-item-category"])) || (isset($query->query_vars["a-dir-item-location"])))) {
$sql = "";
// default ordering
$orderby = (isset($aThemeOptions->directory->defaultOrderby)) ? $aThemeOptions->directory->defaultOrderby : 'post_date';
// get from get parameters
if (!empty($_GET['orderby'])) {
$orderby = $_GET['orderby'];
}
if ($orderby == 'rating') {
$sql .= " LEFT JOIN {$wpdb->postmeta} rating ON ({$wpdb->posts}.ID = rating.post_id AND rating.meta_key IN ('rating_full'))";
//$sql .= " LEFT JOIN {$wpdb->postmeta} rating ON (wp_posts.ID = rating.post_id AND rating.meta_key IN ('rating_full')) LEFT JOIN {$wpdb->postmeta} count ON ({$wpdb->posts} = count.post_id AND count.meta_key IN ('rating_count'))";
}
if ($orderby == 'packages') {
directorySaveUserPackagesToDb();
$sql .= " LEFT JOIN {$wpdb->usermeta} packages ON ({$wpdb->posts}.post_author = packages.user_id AND packages.meta_key IN ('dir_package'))";
}
if (isset($aThemeOptions->directory->showFeaturedItemsFirst)) {
$sql .= " LEFT JOIN {$wpdb->postmeta} featured ON ({$wpdb->posts}.ID = featured.post_id AND featured.meta_key IN ('dir_featured'))";
}
$join .= $sql;
//echo $join;
}
return $join;
}
add_filter('posts_orderby', 'directorySortingOrderby',10,2);
function directorySortingOrderby($orderby, $query) {
global $wpdb, $aThemeOptions;
if ($query->is_main_query() && !$query->is_admin && ((isset($_GET['dir-search'])) || (isset($query->query_vars["a-dir-item-category"])) || (isset($query->query_vars["a-dir-item-location"])))) {
$sql = "";
// default ordering
$orderby = (isset($aThemeOptions->directory->defaultOrderby)) ? $aThemeOptions->directory->defaultOrderby : 'post_date';
$order = (isset($aThemeOptions->directory->defaultOrder)) ? $aThemeOptions->directory->defaultOrder : 'DESC';
// get from get parameters
if (!empty($_GET['orderby'])) {
$orderby = $_GET['orderby'];
}
if (!empty($_GET['order'])) {
$order = $_GET['order'];
}
if ($orderby == 'rating') {
if (isset($aThemeOptions->directory->showFeaturedItemsFirst)) {
$sql = "featured.meta_value DESC, convert(rating.meta_value, decimal) {$order}";
} else {
//$sql = "convert(rating.meta_value, decimal) {$order}";
$sql = "cast(rating.meta_value as decimal(10,2)) {$order}";
//$sql = "cast(rating.meta_value as decimal(10,2)) {$order}, count.meta_value {$order}";
}
} else if ($orderby == 'packages') {
if (isset($aThemeOptions->directory->showFeaturedItemsFirst)) {
$sql = "featured.meta_value DESC, packages.meta_value {$order}";
} else {
$sql = "packages.meta_value {$order}";
}
} else {
if (isset($aThemeOptions->directory->showFeaturedItemsFirst)) {
$sql = "featured.meta_value DESC, {$wpdb->posts}.{$orderby} {$order}";
}
}
$orderby = $sql;
//echo $orderby;
}
return $orderby;
}
// Save directory packages for sorting
function directorySaveUserPackagesToDb() {
$users = get_users();
// capabilities list
$roles = array(
'administrator' => 10,
'directory_5' => 9,
'directory_4' => 8,
'directory_3' => 7,
'directory_2' => 6,
'directory_1' => 5,
'editor' => 4,
'author' => 3,
'contributor' => 2,
'subscriber' => 1
);
foreach ($users as $user) {
if (isset($user->roles[0])) {
if (array_key_exists($user->roles[0], $roles)) {
update_user_meta($user->ID, 'dir_package', $roles[$user->roles[0]]);
} else {
update_user_meta($user->ID, 'dir_package', 0);
}
}
}
}

Answer 1

The MySQL documentation for ORDER BY should be helpful here, particularly the last paragraph on sorting multiple columns.
Your ORDER BY should be something like
ORDER BY rating_full DESC, rating_count DESC