ALTER TABLE vn.expense ADD COLUMN IF NOT EXISTS code VARCHAR(25) DEFAULT NULL NULL, ADD CONSTRAINT expense_UN UNIQUE KEY IF NOT EXISTS (code); CREATE TABLE IF NOT EXISTS sage.`taxType` ( `id` int(11) NOT NULL, `code` varchar(25) DEFAULT NULL, `isIntracommunity` tinyint(1) NOT NULL DEFAULT 0, PRIMARY KEY (`id`), UNIQUE KEY `taxType_UN` (`code`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 COLLATE=utf8mb3_general_ci COMMENT='Coincidencia del id con Sage.TiposIVA.CodigoIva(propia de Sage), en ningĂșn caso vincular mediate FK';