Your current query has a logical error, JOIN condition between balance and user tables is incomplete (missing balance.id_user
). So instead of balance LEFT JOIN user ON user.id_user
you should have balance LEFT JOIN user ON user.id_user=balance.id_user
. This is causing the JOINed table to have more rows (number of rows in balance times number of rows in user table). So the final SUM is bringing a way too higher value.
I tried the following query on your sample data (I changed some values) and it seems to be working fine:
SELECT location_region.name, SUM(balance.value) AS money
FROM balance
LEFT JOIN user USING(id_user)
LEFT JOIN pos USING(id_pos)
LEFT JOIN location_region USING(id_region)
WHERE balance.date BETWEEN '2014-02-01' AND DATE_ADD('2014-02-01', INTERVAL 1 MONTH)
GROUP BY location_region.id_region
ORDER BY money DESC
Working demo: http://sqlfiddle.com/#!2/dda28/3