Simpler ways of calculating years between

Question

Hi again,
I would appreciate numerous versions of calculating years between in years of age
i think there should be simpler ones than this below:
SQL> select floor(months_between(hire_date,dob)/12) age from employee;
AGE
38
32
30
46
39
25
32
46
39
33
10 rows selected.
many thanks
cube60

Answer 1

The EXTRACT approach will return wrong age counts for persons having their birthday in this current month, on a given day in this current month but after today.
Age by minus is also not always accurate.
E.g:
SELECT nr
, birthdate
, trunc( months_between(sysdate,birthdate) / 12 ) age_by_months_between
, trunc((SYSDATE - birthdate)/365.25) age_by_minus
, EXTRACT(YEAR FROM((trunc(SYSDATE)- birthdate)YEAR TO MONTH)) AS age_by_extract
, floor(months_between(trunc(sysdate),birthdate )/12) age_by_floor
FROM <table>
Results:
BIRTHDATE     AGE_BY_MONTHS_BETWEEN     AGE_BY_MINUS     AGE_BY_EXTRACT     AGE_BY_EXTRACT2
23-4-1962     45     45     46     45
25-4-1950     57     57     58     57
15-4-1990     17     17     18     17
21-4-1958     49     49     50     49
20-4-1991     16     16     17     16
26-4-1981     26     26     27     26
14-4-1971     36     36     37     36
15-4-1947     60     60     61     60
12-4-1955     52     53     53     52
12-4-1966     41     42     42     41
12-4-1963     44     45     45     44
12-4-1974     33     34     34     33
12-4-1983     24     25     25     24
12-4-1959     48     49     49     48
12-4-1942     65     66     66     65
12-4-1959     48     49     49     48
12-4-1947     60     61     61     60
25-4-1932     75     75     76     75
It seems that months_between is always correct.
Regards,
MH