根据出生日期计算年龄：

SELECT fbirth,  --出生日期
       date_part('year', age(CAST(fbirth AS DATE))), --年
       date_part('month', age(CAST(fbirth AS DATE))), --月
       date_part('day', age(CAST(fbirth AS DATE)))  --日
  FROM t_noentryquery
 WHERE date_part('year', age(CAST(fbirth AS DATE))) < 18
   AND date_part('year', age(CAST(fbirth AS DATE))) >= 2

下一次生日：

select fbirth,cast(fbirth + ((extract(year from age(fbirth)) + 1) * interval '1' year) as date) as next_birthday
from t_noentryquery