ALTER TABLE `log_table_name`
ADD COLUMN log_id int auto_increment PRIMARY KEY first,
ADD COLUMN log_action VARCHAR(20) AFTER log_id,
ADD COLUMN log_ref INT(20) AFTER log_action,
ADD COLUMN log_ip VARCHAR(15) AFTER log_ref,
ADD COLUMN log_by int(11)AFTER log_ip,
ADD COLUMN log_datetime timestamp AFTER log_by;
