SELECT YEAR FROM DATE FROM VARCHAR2

Question

Dear all,
i have a question aboute date and TO_DATE. The thing is i have a VARCHAR2 colum with data like:
12/09/1979
02/05/1978 etc etc etc
Now we like to know how old the person is at the beginning of the year. So we have to take the current year -1 -year of burth.
The first part is not so hard. We can take the current year from DUAL. Now here is the hard part how do we convert the varchar data to a date and extract only the years from it and not the rest of the date?
All bright and smart things are welcome :-)
Thanks already.

Answer 1

Anupama and Christian,
thanks for the input buth i still have a question. I tried the option of Christian and moddified the query a little:
select months_between(trunc(sysdate, 'YEAR'),
to_date(
'27/08/1979',
'DD/MM/YYYY'
) / 12
from vak_werknemer where geboorte like '__/__/____'
This works fine buth. it is only working with 1 date, so i gives me a list +/1 1000 rows with the same conclusion i am correct aboute my age :-)
Now i like to do this with all the other people in the database. SO i have placed a subquery in the query instead of a date.
select months_between(trunc(sysdate, 'YEAR'),
to_date(
(select geboorte from vak_werknemer where geboorte like '__/__/____'),
'DD/MM/YYYY'
) / 12
from vak_werknemer where geboorte like '__/__/____'
This is giving me the error that a single-row subquery returns more than one row. That is correct there are 1000 returnd rows. How do i make the query so that it will give me a list of all the people and not the age of 1?
Thanks already. :-)