MYSQL knows the date of birth, how to query the age?

1, select id, name, salary, year (birthday)-year (now ()) as age, and department from mm;

2. update mm set salary = (select * from (select AVG (salary) from mm) to tmp), where dept =1003;

3. Select left(aa,100) from tbname;

-Entertainment > Constellation/Fortune

The part of your question is wrong.