The following procedure shows how easy it is to determine the age of someone or something simply using the current date and the birth date (or date of origination):
CREATE PROCEDURE ALTER_IN_JAHREN ( geb date) returns ( alter_in_jahren integer) as declare variable geb_tt integer; declare variable geb_mm integer; declare variable geb_jj integer; declare variable akt_tt integer; declare variable akt_mm integer; declare variable akt_jj integer; declare variable hatte_schon_Geb char(1); begin /* erstellt mit der IBExpert.com Educational version*/ geb_tt=extract(day from geb); geb_mm=extract(month from geb); geb_jj=extract(year from geb); akt_tt=extract(day from current_date); akt_mm=extract(month from current_date); akt_jj=extract(year from current_date); hatte_schon_Geb='N'; if (geb_mm<akt_mm) then hatte_schon_Geb='J'; else if ((geb_mm=akt_mm) and (geb_tt<=akt_tt)) then hatte_schon_Geb='J'; alter_in_jahren=akt_jj-geb_jj-1; if (hatte_schon_geb='J') then alter_in_jahren=alter_in_jahren+1; suspend; end