Re: subtracting from a date - Mailing list pgsql-general

On 02/06/2014 09:25 AM, Jay Vee wrote:

I have reviewed working with dates documentation but some things are not
clear and I cannot get an example to work for what I need.

I am passing a date into a stored function like '2013-04-01'

The stored function accepts this string as a date type.

Within the function, I need to:
1.  subtract one year from this date into another date type
2.  subtract one month from this date into another date type
3.  subtract one day from this date into another date type

Are there any examples of this?  This is not a timestamp type, but a
date type.

Something like this:

test=> select '2013-04-01'::date - interval '1 yr';
      ?column?
---------------------
 2012-04-01 00:00:00
(1 row)

test=> select '2013-04-01'::date - interval '1 month';
      ?column?
---------------------
 2013-03-01 00:00:00
(1 row)

test=> select '2013-04-01'::date - interval '1 day';
      ?column?
---------------------
 2013-03-31 00:00:00


You did say what language you are using for the function so the assignment will depend on that.

thanks

--
Adrian Klaver
adrian.klaver@gmail.com