Question

I need to obtain the last two digits of an integer. Each element placed in the tables comes as a full year ie. YYYY and I only want the last two digits, so that all the fields show

YEAR
----
09
00
89

where the initialy field was

YEAR
----
2009
2000
1989

EDIT: I get a complaint saying,

HINT: No function matches the given name and argument types. You might need to add explicit type casts.

when i try

select right(cast(year as char),2) from subjects;

Answer 1

Postgres has borrowed (or inherited) the modulus operator from C:

SET search_path='tmp';

CREATE TABLE lutser ( year integer);

INSERT INTO lutser (year)
        SELECT generate_series(1991,2012)
    ;

SELECT year
    , year / 100 as c2
    , year % 100 AS y2
    FROM lutser
    ;

Result:

CREATE TABLE
INSERT 0 22
 year | c2 | y2 
------+----+----
 1991 | 19 | 91
 1992 | 19 | 92
 1993 | 19 | 93
 1994 | 19 | 94
 1995 | 19 | 95
 1996 | 19 | 96
 1997 | 19 | 97
 1998 | 19 | 98
 1999 | 19 | 99
 2000 | 20 |  0
 2001 | 20 |  1
 2002 | 20 |  2
 2003 | 20 |  3
 2004 | 20 |  4
 2005 | 20 |  5
 2006 | 20 |  6
 2007 | 20 |  7
 2008 | 20 |  8
 2009 | 20 |  9
 2010 | 20 | 10
 2011 | 20 | 11
 2012 | 20 | 12
(22 rows)