Calculating Age from Date of Birth with where condition on Age in MySQL

Question

How to calculate age with where condition on age again ? I want all users only of age < 50 year

My query is working fine without where condition but when i am adding WHERE age < 50 it's give me an error #1054 - Unknown column 'age' in 'where clause'

SELECT u.*, YEAR(CURRENT_TIMESTAMP) - YEAR(u.user_dob) - (RIGHT(CURRENT_TIMESTAMP, 5) < 
RIGHT(u.user_dob, 5)) as age FROM tbl_users as u WHERE age < 50 

Answer 1

How about something simpler like this?

where dob >= date_sub(curdate(), interval 50 year)

If you want the age, you can take the difference in years:

select timestampdiff(year, dob, curdate())

Answer 2

update your age in where clause with this:

YEAR(CURRENT_TIMESTAMP) - YEAR(u.user_dob) - (
RIGHT(CURRENT_TIMESTAMP, 5) <
RIGHT(u.user_dob, 5))

to be:

SELECT u.*, YEAR(CURRENT_TIMESTAMP) - YEAR(u.user_dob) - (
RIGHT(CURRENT_TIMESTAMP, 5) <
RIGHT(u.user_dob, 5)) AS age
FROM tbl_users AS u
WHERE YEAR(CURRENT_TIMESTAMP) - YEAR(u.user_dob) - (
RIGHT(CURRENT_TIMESTAMP, 5) <
RIGHT(u.user_dob, 5)) < 50