CREATE OR REPLACE FUNCTION calculate_network(INTEGER,INTEGER)
RETURNS void AS
$$
WITH RECURSIVE all_friends AS
(
        SELECT befreundetmit,freundvon,freundschaftsgrad FROM istbefreundetmit
        UNION
           SELECT af.befreundetmit,f.freundvon,af.freundschaftsgrad
           FROM all_friends af join istbefreundetmit f
           ON af.freundvon = f.befreundetmit
)
SELECT DISTINCT count(*)
FROM all_friends
WHERE freundvon = $1 AND freundschaftsgrad > $2 AND befreundetmit != $1;


UPDATE freunde SET anzahl = (SELECT DISTINCT count(*)
                            FROM all_friends
                            WHERE freundvon = $1 AND freundschaftsgrad > $2 AND befreundetmit != $1)
WHERE freundid = $1;

$$
language 'sql';