创建mysql函数 fun_Knowledge_child_url, 输入一个int类型节点chId,return一个url字符串
BEGIN
DECLARE sTemp VARCHAR(1000);
DECLARE sTempChd VARCHAR(1000);
DECLARE knoName VARCHAR(100);
DECLARE tempPid INT;
SET sTemp = '$';
SET knoName = '$';
SET tempPid = chId;
SELECT t3.`name` into sTemp FROM mooc_si_knowledge_tree t3 where t3.id = chId;
WHILE tempPid>0 DO
SELECT t.pId into tempPid FROM mooc_si_knowledge_tree t where t.id = tempPid;
IF tempPid>0
THEN
SELECT t2.`name` INTO knoName FROM mooc_si_knowledge_tree t2 where t2.id=tempPid;
SET sTemp = CONCAT(knoName,'/',sTemp);
END IF;
END WHILE;
RETURN sTemp;
END