mysql update语句

单表更新
UPDATE a
SET a.age = 20
WHERE a.age > 10

多表更新 update join
UPDATE a
INNER JOIN b ON a.id = b.id
SET a.age = b.age
WHERE a.age > 10

多表更新 update 表1,表2...
UPDATE a,b
SET a.age = b.age
WHERE a.id = b.id AND a.age > 10