mysql遍历节点的所有子节点

DELIMITER //

CREATE FUNCTION `getChildrenList`(rootId INT)

RETURNS VARCHAR(500)

BEGIN

DECLARE sTemp VARCHAR(500);

DECLARE sTempChd VARCHAR(1000);

SET sTemp = '';

SET sTempChd =CAST(rootId AS CHAR);

WHILE sTempChd IS NOT NULL DO

SET sTemp = CONCAT(sTemp,',',sTempChd);

SELECT GROUP_CONCAT(id) INTO sTempChd FROM employees WHERE FIND_IN_SET(parent_id,sTempChd)>0;

END WHILE;

RETURN sTemp;

END

SELECT getChildrenList(2);