单表更新UPDATE aSET a.age = 20WHERE a.age > 10
多表更新 update joinUPDATE aINNER JOIN b ON a.id = b.idSET a.age = b.ageWHERE a.age > 10
多表更新 update 表1,表2...UPDATE a,bSET a.age = b.ageWHERE a.id = b.id AND a.age > 10