Return rows when there is a certain difference between dates

Question

Hello.
I have table called
#president#
pres_name
birth_date
and
#winner#
name
year_elected
I would like to have all presidents returned, who where under the age 50 when they where elected.
year_elected is only a 4 digit number; 1924 etc while birth_date is 2001-01-01 etc.
I have no idea how to make this work, ive tried substr and alot of other weird (and prob wrong) stuff.
select distinct p.pres_name, substr(p.birth_date, 0, 4), w.year_elected
from president p, winner w
where p.pres_name = w.nameI did this query witch will show me all presidents, and their dates of election and date of birth. Now i just want something that only returns the guys where its a 49 (?) value difference between birth_date and year_elected
Johan
Edited by: user10248089 on 2008-okt-02 00:42

Answer 1

Based on Dave's information about presidents being elected on first Tuesday in Nov...
SQL> with president as (select 'Bob' as pres_name, to_date('1/7/1934','DD/MM/YYYY') as birth_date from dual union all
  2                     select 'Fred', to_date('13/5/1950','DD/MM/YYYY') from dual union all
  3                     select 'Jim', to_date('21/12/1960','DD/MM/YYYY') from dual)
  4      ,winner    as (select 'Bob' as name, '1979' as year_elected from dual union all
  5                     select 'Fred', '2005' from dual union all
  6                     select 'Jim', '2000' from dual)
  7  --
  8  select p.pres_name, p.birth_date, w.year_elected
  9        ,trunc(months_between(next_day(to_date('01/11/'||w.year_elected,'DD/MM/YYYY'),'TUE'),birth_date)/12) as age
10  from president p join winner w on (p.pres_name = w.name)
11  /
PRES BIRTH_DAT YEAR        AGE
Bob  01-JUL-34 1979         45
Fred 13-MAY-50 2005         55
Jim  21-DEC-60 2000         39
SQL>And the WHERE clause can be applied based on the same calculation as shown in the age column