join to other table multiplied by loop foreign key in mysql

i have 2 table one node and relation and Second store buy each node. my code work fine but when sum multiple buy for each node result multiplied by number of purchases . table nodes +-------------+---------------+-------------+ | ancestor_id | descendant_id | path_length | +-------------+---------------+-------------+ | 1 | 1 | 0 | | 1 | 2 | 1 | | 1 | 3 | 2 | | 1 | 4 | 1 | | 1 | 5 | 2 | | 1 | 6 | 3 | | 1 | 7 | 4 | | 2 | 2 | 0 | | 2 | 3 | 1 | | 2 | 5 | 1 | | 2 | 6 | 2 | | 2 | 7 | 3 | | 3 | 3 | 0 | | 4 | 4 | 0 | | 5 | 5 | 0 | | 5 | 6 | 1 | | 5 | 7 | 2 | | 6 | 6 | 0 | | 6 | 7 | 1 | | 7 | 7 | 0 | +-------------+---------------+-------------+ table buy +-------------+---------------+-------------+ | userid | amount | +-------------+---------------+-------------+ | 2 | 1500 | | 7 | 2000 | +-------------+---------------+-------------+ mysql code SELECT DISTINCT users.descendant_id , SUM(CASE WHEN ances.ancestor_id = buys_ances.userid THEN 1 ELSE 0 END) level_compress FROM webineh_prefix_nodes_paths as users join webineh_user_buys as buys on (users.descendant_id = buys.userid ) join webineh_prefix_nodes_paths as ances on (users.descendant_id = ances.descendant_id ) join webineh_user_buys as buys_ances on (buys_ances.userid = ances.ancestor_id ) WHERE users.ancestor_id = 1 and (SELECT SUM(g2.amount) as amount FROM webineh_user_buys g2 where g2.userid = ances.ancestor_id group by g2.userid ) >= 1000 and (SELECT SUM(g1.amount) as amount FROM webineh_user_buys g1 where g1.userid = users.descendant_id group by g1.userid ) >= 1000 group by buys.userid ,ances.ancestor_id result when in curent purchases data users.descendant_id | users.ancestor_id | level_compress 2 | | 1 6 | | 2 **i need to show ancestor_id compressed id**