wpdb::placeholder_escape()
Method: Generates and returns a placeholder escape string for use in queries returned by ::prepare().
Source: wp-includes/class-wpdb.php:2398
wpdb::add_placeholder_escape()
Method: Adds a placeholder escape string, to escape anything that resembles a printf() placeholder.
Source: wp-includes/class-wpdb.php:2429
wpdb::remove_placeholder_escape()
Method: Removes the placeholder escape strings from a query.
Source: wp-includes/class-wpdb.php:2445