Andrzej Banach napisał(a):

A moze ktos powie jak uproscic te zapytanie by wyszukiwanie bilansu i danych abonenta twalo krocej??

nie potrzebujesz złaczenia z nodes:

SELECT customers.id AS id, customers.lastname AS lastname, customers.name AS name, ROUND(SUM((type * -2 + 7) * value),2) AS balance FROM customers LEFT JOIN cash ON (customers.id = customerid) WHERE deleted = 0 GROUP BY customers.id, lastname, customers.name