Per questo è necessario disporre di una funzione memorizzata:
DELIMITER $$
DROP FUNCTION IF EXISTS `junk`.`GetFamilyTree` $$
CREATE FUNCTION `GetFamilyTree` (GivenID VARCHAR(1024)) RETURNS varchar(1024) CHARSET latin1
DETERMINISTIC
BEGIN
DECLARE rv,q,queue,queue_children,front_id VARCHAR(1024);
DECLARE queue_length,pos INT;
SET rv = '';
SET queue = GivenID;
SET queue_length = 1;
WHILE queue_length > 0 DO
SET front_id = queue;
IF queue_length = 1 THEN
SET queue = '';
ELSE
SET pos = LOCATE(',',queue) + 1;
SET q = SUBSTR(queue,pos);
SET queue = q;
END IF;
SET queue_length = queue_length - 1;
SELECT IFNULL(qc,'') INTO queue_children
FROM (SELECT GROUP_CONCAT(id) qc
FROM Table1 WHERE manager = front_id) A;
IF LENGTH(queue_children) = 0 THEN
IF LENGTH(queue) = 0 THEN
SET queue_length = 0;
END IF;
ELSE
IF LENGTH(rv) = 0 THEN
SET rv = queue_children;
ELSE
SET rv = CONCAT(rv,',',queue_children);
END IF;
IF LENGTH(queue) = 0 THEN
SET queue = queue_children;
ELSE
SET queue = CONCAT(queue,',',queue_children);
END IF;
SET queue_length = LENGTH(queue) - LENGTH(REPLACE(queue,',','')) + 1;
END IF;
END WHILE;
RETURN rv;
END $$
Quindi puoi chiamare come :
SELECT `id`, `manager`,GetFamilyTree(`id`) as children
from Table1;
Puoi anche avere filtri:
SELECT `id`, `manager`,GetFamilyTree(`id`) as children
from Table1 where `id` = 'james';
