#THIS WORKS FOR POSTGRES and MYSQL
# You can use the AGE function. The AGE function requires two arguementS.
# AGE(late date, early date). The NOW() function returns the current timestamp.
AGE(NOW(), date_of_birth) AS age
#Since NOW() is a timestamp, the result will be like this:
# 45 years 2 months 15 days 21:43:05.378372
#You can then use this to extract the age.
LEFT(age, STRPOS(age,' '))