Answers for "mysql update two columns at once"

mysql update two tables at once

UPDATE t1 LEFT JOIN t2 ON t1.id = t2.f_key
   SET t1.value = t1.value + 1,
       t2.value = t2.value + 1
 WHERE t1.id = condition

mysql update one table from another table multiple columns

update  tabe2 set subject_id = (SELECT GROUP_CONCAT(sub_id SEPARATOR ', ') as sub_id FROM tabe1)