Postgres birthdays selection

Question

I work with a Postgres database. This DB has a table with users, who have a birthdate (date field). Now I want to get all users who have their birthday in the upcoming week.

Answer 1

First find out how old the person currently is using age(), then grab the year from that extract(year from age()). This is how old they are currently in years, so for their age at their next birthday add 1 to the year. Then their next birthday is found by adding an interval of this many years * interval '1 year' to their birthday. Done.

I've used a subselect here to add the next_birth_day column in to the complete table to make the select clause simpler. You can then play with the where conditions to suit your needs.

select * 
from (
     select *, 
       (extract(year from age(birth_date)) + 1) *  interval '1 year' + birth_date "next_birth_day"
      from public.users
) as users_with_upcoming_birth_days
where next_birth_day between now() and now() + '7 days'