Re: extract or date_part on an interval? How many e

On Jan 27, 2008, at 23:51 , Bryce Nesbitt wrote:

> Sigh. Ok, I settled on:
> select '1987-01-29'::timestamp + interval '21 years' > now();
> Which is closer to what I wanted anyway (this was all about  
> determining who was under 21 years old).  This at least should be  
> robust over leap years.

I think this should work for you for your particular case:

EXTRACT(year FROM AGE(born_on)) >= 21
 SELECT born_on, current_date, age(born_on), EXTRACT(year FROM AGE 
(born_on)) AS age_in_years, EXTRACT(year FROM age(born_on)) >= 21 as  
old_enough_to_drink FROM (SELECT CAST('1987-01-25' AS DATE) + i AS  
born_on FROM generate_series(0,5) as the(i)) foo;  born_on   |    date    |           age            | age_in_years |

old_enough_to_drink
------------+------------+--------------------------+-------------- 
+--------------------- 1987-01-25 | 2008-01-28 | 21 years 3 days          |           21 | t 1987-01-26 | 2008-01-28 |
21years 2 days          |           21 | t 1987-01-27 | 2008-01-28 | 21 years 1 day           |           21 | t
1987-01-28| 2008-01-28 | 21 years                 |           21 | t 1987-01-29 | 2008-01-28 | 20 years 11 mons 30 days
|          20 | f 1987-01-30 | 2008-01-28 | 20 years 11 mons 29 days |           20 | f
 
(6 rows)

Michael Glaesemann
grzm seespotcode net