Counting number of medals in weekly tournaments - sql

Question

I have a table holding weekly scores of players:
# select * from pref_money limit 5;
id | money | yw
----------------+-------+---------
OK32378280203 | -27 | 2010-44
OK274037315447 | -56 | 2010-44
OK19644992852 | 8 | 2010-44
OK21807961329 | 114 | 2010-44
FB1845091917 | 774 | 2010-44
(5 rows)
This SQL statement gets me the weekly winners and how many times each player has won:
# select x.id, count(x.id) from (
select id,
row_number() over(partition by yw order by money desc) as ranking
from pref_money
) x
where x.ranking = 1 group by x.id;
id | count
------------------------+-------
OK9521784953 | 1
OK356310219480 | 1
MR797911753357391363 | 1
OK135366127143 | 1
OK314685454941 | 1
OK308121034308 | 1
OK4087658302 | 5
OK452217781481 | 6
....
I would like to save the latter number in the medals column of the players table:
# \d pref_users;
Table "public.pref_users"
Column | Type | Modifiers
------------+-----------------------------+--------------------
id | character varying(32) | not null
first_name | character varying(64) |
last_name | character varying(64) |
city | character varying(64) |
medals | integer | not null default 0
How to do this please? I can only think of using a temporary table, but there must be an easier way... Thank you
UPDATE:
The query suggested by Clodoaldo works, but now my cronjob occasionally fails with:
/* reset and then update medals count */
update pref_users set medals = 0;
psql:/home/afarber/bin/clean-database.sql:63: ERROR: deadlock detected
DETAIL: Process 31072 waits for ShareLock on transaction 124735679; blocked by process 30368.
Process 30368 waits for ShareLock on transaction 124735675; blocked by process 31072.
HINT: See server log for query details.
update pref_users u
set medals = s.medals
from (
select id, count(id) medals
from (
select id,
row_number() over(partition by yw order by money desc) as ranking
from pref_money where yw <> to_char(CURRENT_TIMESTAMP, 'IYYY-IW')
) x
where ranking = 1
group by id
) s
where u.id = s.id;

Answer 1

update pref_users u
set medals = s.medals
from (
select id, count(id) medals
from (
select id,
row_number() over(partition by yw order by money desc) as ranking
from pref_money
) x
where ranking = 1
group by id
) s
where u.id = s.id

Answer 2

You could create a view which uses your "medal-select" and joins it with the actual data:
CREATE VIEW pref_money_medals AS
SELECT *
FROM pref_money
JOIN (SELECT count(x.id)
FROM (SELECT id, row_number()
OVER(PARTITION BY yw ORDER BY money DESC) AS ranking
FROM pref_money
) x
WHERE x.ranking = 1 group by x.id) medals
ON pref_money.id = medals.id;