data-delete.php

<?php

/**
 * Delete dt_subscription posts and associated postmeta from the database.
 */
function delete_site_post_data() {
	global $wpdb;

	// Get all subscription IDs.
	$subscription_post_ids = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE post_type = 'dt_subscription';" );

	// Delete subscription meta.
	$wpdb->query(
		$wpdb->prepare(
			sprintf(
				"DELETE FROM $wpdb->postmeta WHERE post_id IN ( %s );",
				implode( ',', array_fill( 0, count( $subscription_post_ids ), '%s' ) )
			),
			$subscription_post_ids
		)
	);

	// Delete subscription posts.
	$wpdb->query(
		$wpdb->prepare(
			sprintf(
				"DELETE FROM $wpdb->posts WHERE ID IN ( %s );",
				implode( ',', array_fill( 0, count( $subscription_post_ids ), '%s' ) )
			),
			$subscription_post_ids
		)
	);

	// Clear the post cache.
	wp_cache_set_posts_last_changed();
	wp_cache_delete_multiple( $subscription_post_ids, 'posts' );
	wp_cache_delete_multiple( $subscription_post_ids, 'post_meta' );
}

/**
 * Delete all options from a single site.
 */
function delete_site_options() {
	global $wpdb;

	$option_prefixes = array(
		'dt_',
		'_transient_dt_',
		'_transient_timeout_dt_',
	);

	if ( ! is_multisite() ) {
		$option_prefixes[] = '_site_transient_dt_';
		$option_prefixes[] = '_site_transient_timeout_dt_';
	}

	$options_to_delete = $wpdb->get_results(
		$wpdb->prepare(
			sprintf(
				"SELECT option_name, autoload FROM $wpdb->options WHERE 1 = 1 AND ( %s );",
				implode( ' OR ', array_fill( 0, count( $option_prefixes ), 'option_name LIKE %s' ) )
			),
			array_map( function( $prefix ) use ( $wpdb ) {
				return $wpdb->esc_like( $prefix ) . '%';
			}, $option_prefixes )
		)
	);

	$autoload_values = function_exists( 'wp_autoload_values_to_autoload' )
		? wp_autoload_values_to_autoload()
		: array( 'yes' );

	$autoloaded_options = array_filter( $options_to_delete, function( $option ) use ( $autoload_values ) {
		return in_array( $option->autoload, $autoload_values );
	} );

	$not_autoloaded_options = array_filter( $options_to_delete, function( $option ) use ( $autoload_values ) {
		return ! in_array( $option->autoload, $autoload_values );
	} );

	// Delete all the options using the retrieved option names.
	$wpdb->query(
		$wpdb->prepare(
			sprintf(
				"DELETE FROM $wpdb->options WHERE 1 = 1 AND ( %s );",
				implode( ' OR ', array_fill( 0, count( $options_to_delete ), 'option_name = %s' ) )
			),
			array_map( function( $option ) {
				return $option->option_name;
			}, $options_to_delete )
		)
	);

	// Flush the alloptions cache if any options were autoloaded.
	if ( ! empty( $autoloaded_options ) ) {
		wp_cache_delete( 'alloptions', 'options' );
	}

	// Flush the individual caches for options that were not autoloaded.
	$not_all_option_names = wp_list_pluck( $not_autoloaded_options, 'option_name' );
	wp_cache_delete_multiple( $not_all_option_names, 'options' );
}

/**
 * Delete all site options from a multisite install.
 */
function delete_multisite_site_options() {
	global $wpdb;

	$option_prefixes = array(
		'dt_',
		'_site_transient_dt_',
		'_site_transient_timeout_dt_',
	);

	$options_to_delete = $wpdb->get_results(
		$wpdb->prepare(
			sprintf(
				"SELECT meta_key FROM $wpdb->sitemeta WHERE 'site_id' = %d AND ( %s );",
				get_current_network_id(),
				implode( ' OR ', array_fill( 0, count( $option_prefixes ), 'meta_key LIKE %s' ) )
			),
			array_map( function( $prefix ) use ( $wpdb ) {
				return $wpdb->esc_like( $prefix ) . '%';
			}, $option_prefixes )
		)
	);

	// Delete all the options using the retrieved option names.
	$wpdb->query(
		$wpdb->prepare(
			sprintf(
				"DELETE FROM $wpdb->sitemeta WHERE 'site_id' = %d AND ( %s );",
				get_current_network_id(),
				implode( ' OR ', array_fill( 0, count( $options_to_delete ), 'meta_key = %s' ) )
			),
			array_map( function( $option ) {
				return $option->meta_key;
			}, $options_to_delete )
		)
	);

	// Flush the option caches.
	$option_names = wp_list_pluck( $options_to_delete, 'meta_key' );
	$option_cache_keys = array_map( function( $option_name ) {
		return get_current_network_id() . ":$option_name";
	}, $option_names );

	wp_cache_delete_multiple( $option_cache_keys, 'site-options' );
}