wordpress update query example
$sql = "UPDATE `dbname`.`wp_terms` SET `slug` = REPLACE(`slug`, \'--\', \'-\') WHERE `slug` LIKE \'%--%\' COLLATE utf8_bin";
$sql = "UPDATE `dbname`.`wp_terms` SET `slug` = REPLACE(`slug`, \'--\', \'-\') WHERE `slug` LIKE \'%--%\' COLLATE utf8_bin";