How delete data from other table - WordPress - php

Question

I am trying to delete data from another table using before_delete_post. However, my script does not work. My before_delete_post is at the top of the code. The effect I would like to get when deleting a post would be to delete the data from another table(wp_used_cars) with the same id.
add_action( 'before_delete_post', 'my_func' );
function my_func( $postid ){
global $post_type;
if ( $post_type != 'my_custom_post_type' ) return;
$post_type->query( $wpdb->prepare( 'DELETE FROM wp_used_cars WHERE post_id = %d', $postid ) );
}
// -------------------------------------------------------------------------
// add custom posts --------------------------------------------------------
// add uzywane custom post and set custom capabilities
$uzywane = new CustomPost('uzywane');
$uzywane->make('Uzywane', 'Uzywane', 'Uzywane', array(
'capabilities' => array(
'edit_post' => 'edit_used_car',
'read_post' => 'read_used_car',
'delete_post' => 'delete_used_car',
'edit_posts' => 'edit_used_cars',
'edit_others_posts' => 'edit_others_used_cars',
'publish_posts' => 'publish_used_cars',
'read_private_posts' => 'read_private_used_cars',
),
));
// add this custom capabilities to admin
$role = get_role( 'administrator' );
$role->add_cap( 'edit_used_car', true );
$role->add_cap( 'read_used_car', true );
$role->add_cap( 'delete_used_car', true );
$role->add_cap( 'edit_used_cars', true );
$role->add_cap( 'edit_others_used_cars', true );
$role->add_cap( 'publish_used_cars', true );
$role->add_cap( 'read_private_used_cars', true );
// if role uzywane don't exists add it and set capabilities to edit uzywane
if( ! role_exists( 'uzywane' ) ) {
add_role(
'uzywane',
__( 'Używane' ),
array(
'read' => true,
'edit_used_car' => true,
'read_used_car' => true,
'delete_used_car' => true,
'edit_used_cars' => true,
'edit_others_used_cars' => true,
'publish_used_cars' => true,
'read_private_used_cars'=> true,
'unfiltered_upload' => true,
'upload_files' => true,
'edit_posts' => true,
)
);
}
// if user has role uzywane than remove links from admin panel
$user = wp_get_current_user();
if ( in_array( 'uzywane', (array) $user->roles ) ) {
function remove_links() {
echo '<style>.menu-icon-post, .menu-icon-promo_posts, .menu-icon-serwis, .menu-icon-nowe, .menu-icon-silniki, .menu-icon-comments, #toplevel_page_wpcf7, .menu-icon-tools, #wp-admin-bar-new-content, #wp-admin-bar-wpseo-menu, #wp-admin-bar-comments, .update-nag {display: none;}</style>';
}
add_action('admin_head', 'remove_links');
}
// if role uzywane don't exists add it and set capabilities to edit uzywane
if( ! role_exists( 'uzywane-admin' ) ) {
add_role(
'uzywane-admin',
__( 'Używane-admin' ),
array(
'read' => true,
'edit_used_car' => true,
'read_used_car' => true,
'delete_used_car' => true,
'edit_used_cars' => true,
'edit_others_used_cars' => true,
'publish_used_cars' => true,
'read_private_used_cars'=> true,
'unfiltered_upload' => true,
'upload_files' => true,
'edit_posts' => true,
'edit_others_posts' => true,
'manage_options' => true,
)
);
}
// if user has role uzywane than remove links from admin panel
$user = wp_get_current_user();
if ( in_array( 'uzywane-admin', (array) $user->roles ) ) {
function remove_links() {
echo '<style> #toplevel_page_revslider, #toplevel_page_revslider, #menu-settings, #toplevel_page_wpseo_dashboard, #toplevel_page_edit-post_type-search-filter-widget, #toplevel_page_easy-responsive-tabs, .menu-icon-post, .menu-icon-promo_posts, .menu-icon-serwis, .menu-icon-nowe, .menu-icon-silniki, .menu-icon-comments, #toplevel_page_wpcf7, .menu-icon-tools, #wp-admin-bar-new-content, #wp-admin-bar-wpseo-menu, #wp-admin-bar-comments, .update-nag, #toplevel_page_edit-post_type-acf-field-group .wp-submenu li, #menu-appearance, .acf-columns-2 .wp-list-table.widefat tr, #acf-field-group-locations, #mymetabox_revslider_0, #acf-field-group-options {display: none;} .wp-list-table.widefat tr#post-456 {display: block };</style>';
}
add_action('admin_head', 'remove_links');
}
function cat_for_used_cars() {
$labels = array(
'name' => _x( 'Kategorie samochodów', 'Taxonomy General Name', 'text_domain' ),
'singular_name' => _x( 'Kategoria samochodów', 'Taxonomy Singular Name', 'text_domain' ),
'menu_name' => __( 'Kategoria samochodów', 'text_domain' ),
'all_items' => __( 'Wszystkie samochodów', 'text_domain' ),
'parent_item' => __( 'Parent Item', 'text_domain' ),
'parent_item_colon' => __( 'Parent Item:', 'text_domain' ),
'new_item_name' => __( 'Nazwa', 'text_domain' ),
'add_new_item' => __( 'Dodaj', 'text_domain' ),
'edit_item' => __( 'Edycja', 'text_domain' ),
'update_item' => __( 'Update Item', 'text_domain' ),
'view_item' => __( 'View Item', 'text_domain' ),
'separate_items_with_commas' => __( 'Separate items with commas', 'text_domain' ),
'add_or_remove_items' => __( 'Add or remove items', 'text_domain' ),
'choose_from_most_used' => __( 'Choose from the most used', 'text_domain' ),
'popular_items' => __( 'Popular Items', 'text_domain' ),
'search_items' => __( 'Search Items', 'text_domain' ),
'not_found' => __( 'Not Found', 'text_domain' ),
'no_terms' => __( 'No items', 'text_domain' ),
'items_list' => __( 'Items list', 'text_domain' ),
'items_list_navigation' => __( 'Items list navigation', 'text_domain' ),
);
$args = array(
'labels' => $labels,
'hierarchical' => true,
'public' => true,
'show_ui' => true,
'show_in_menu' => true,
'show_admin_column' => true,
'show_in_nav_menus' => false,
'show_tagcloud' => false,
'rewrite' => false,
);
register_taxonomy( 'usedcars', array( 'uzywane' ), $args );
}
add_action( 'init', 'cat_for_used_cars', 0 );

Answer 1

Try Below code :
add_action( 'before_delete_post', 'my_func' );
function my_func( $postid )
{
global $post_type;
if ( $post_type != 'uzywane' )
return;
global $wpdb;
$prefix = $wpdb->prefix;
$tbl = $prefix.'used_cars';
$used_cars_count = $wpdb->get_var( "SELECT COUNT(*) FROM $tbl where post_id = ". $postid );
if($used_cars_count > 0)
{
$wpdb->delete( $tbl, array( 'post_id' => $postid ) );
}
}
Hope this will help you!