_find_post_by_old_slug()

_find_post_by_old_slug( string $post_type ): int

function _find_post_by_old_slug( $post_type ) {
	global $wpdb;

	$query = $wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta, $wpdb->posts WHERE ID = post_id AND post_type = %s AND meta_key = '_wp_old_slug' AND meta_value = %s", $post_type, get_query_var( 'name' ) );

	/*
	 * If year, monthnum, or day have been specified, make our query more precise
	 * just in case there are multiple identical _wp_old_slug values.
	 */
	if ( get_query_var( 'year' ) ) {
		$query .= $wpdb->prepare( ' AND YEAR(post_date) = %d', get_query_var( 'year' ) );
	}
	if ( get_query_var( 'monthnum' ) ) {
		$query .= $wpdb->prepare( ' AND MONTH(post_date) = %d', get_query_var( 'monthnum' ) );
	}
	if ( get_query_var( 'day' ) ) {
		$query .= $wpdb->prepare( ' AND DAYOFMONTH(post_date) = %d', get_query_var( 'day' ) );
	}

	$key          = md5( $query );
	$last_changed = wp_cache_get_last_changed( 'posts' );
	$cache_key    = "find_post_by_old_slug:$key";
	$cache        = wp_cache_get_salted( $cache_key, 'post-queries', $last_changed );
	if ( false !== $cache ) {
		$id = $cache;
	} else {
		$id = (int) $wpdb->get_var( $query );
		wp_cache_set_salted( $cache_key, $id, 'post-queries', $last_changed );
	}

	return $id;
}