MySQL遞歸查詢樹狀表的子節點、父節點具體實作

mysql版本（5.5、6等等）尚未支援循環遞歸查詢，和sqlserver、oracle相比，mysql難于在樹狀表中層層周遊的子節點。本程式重點參考了下面的資料，寫了兩個sql存儲過程，子節點查詢算是照搬了，父節點查詢是逆思維弄的。

表結構和表資料就不公示了，查詢的表user_role，主鍵是id，每條記錄有parentid字段（對應該記錄的父節點，當然，一個父節點自然會有一個以上的子節點嘛）

CREATE FUNCTION `getChildList`(rootId INT)
RETURNS varchar(1000)
BEGIN
DECLARE sChildList VARCHAR(1000);
DECLARE sChildTemp VARCHAR(1000);
SET sChildTemp =cast(rootId as CHAR);
WHILE sChildTemp is not null DO
IF (sChildList is not null) THEN
SET sChildList = concat(sChildList,',',sChildTemp);
ELSE
SET sChildList = concat(sChildTemp);
END IF;
SELECT group_concat(id) INTO sChildTemp FROM user_role where FIND_IN_SET(parentid,sChildTemp)>0;
END WHILE;
RETURN sChildList;
END;
/*擷取子節點*/
/*調用: 1、select getChildList(0) id; 2、select * 5From user_role where FIND_IN_SET(id, getChildList(2));*/ 
      

CREATE FUNCTION `getParentList`(rootId INT)
RETURNS varchar(1000)
BEGIN
DECLARE sParentList varchar(1000);
DECLARE sParentTemp varchar(1000);
SET sParentTemp =cast(rootId as CHAR);
WHILE sParentTemp is not null DO
IF (sParentList is not null) THEN
SET sParentList = concat(sParentTemp,',',sParentList);
ELSE
SET sParentList = concat(sParentTemp);
END IF;
SELECT group_concat(parentid) INTO sParentTemp FROM user_role where FIND_IN_SET(id,sParentTemp)>0;
END WHILE;
RETURN sParentList;
END;
/*擷取父節點*/
/*調用: 1、select getParentList(6) id; 2、select * From user_role where FIND_IN_SET(id, getParentList(2));*/