SQL Server 樹形表非循環(huán)遞歸查詢的實例詳解

2024-08-31 01:04:13

字體：大中小

供稿：網(wǎng)友

很多人可能想要查詢整個樹形表關(guān)聯(lián)的內(nèi)容都會通過循環(huán)遞歸來查...事實上在微軟在SQL2005或以上版本就能用別的語法進行查詢，下面是示例。

--通過子節(jié)點查詢父節(jié)點WITH TREE AS( SELECT * FROM Areas WHERE id = 6 -- 要查詢的子 id UNION ALL SELECT Areas.* FROM Areas, TREE WHERE TREE.PId = Areas.Id) SELECT Area FROM TREE--通過父節(jié)點查詢子節(jié)點WITH TREE AS( SELECT * FROM Areas WHERE id = 7 -- 要查詢的子 id UNION ALL SELECT Areas.* FROM Areas, TREE WHERE TREE.Id = Areas.PId) SELECT Area FROM TREE

通過子節(jié)點查詢父節(jié)點查詢結(jié)果為：

sql,server,樹形查詢,sqlserver遞歸查詢

修改代碼為

--通過子節(jié)點查詢父節(jié)點declare @area varchar(8000);WITH TREE AS( SELECT * FROM Areas WHERE id = 6 -- 要查詢的子 id UNION ALL SELECT Areas.* FROM Areas, TREE WHERE TREE.PId = Areas.Id)select @area=isnull(@area,'')+Area from Tree order by id select Area= @area

則結(jié)果為：中國北京市豐臺區(qū)

根據(jù)以上可以將這段代碼封裝為一個存儲過程

-----存儲過程，遞歸獲取樹形地區(qū)表字符串if exists (select * from sysobjects where name='SP_GetAreaStr')drop proc SP_GetAreaStrgocreate procedure SP_GetAreaStr @id intasdeclare @area varchar(8000)beginWITH TREE AS( SELECT * FROM Areas WHERE id = @id -- 要查詢的子 id UNION ALL SELECT Areas.* FROM Areas, TREE WHERE TREE.PId = Areas.Id)select @area=isnull(@area,'')+Area from Tree order by id select Area= @areaend go--exec sp_helptext 'SP_GetAreaStr'--goexec SP_GetAreaStr 28go

查詢結(jié)果：中國安徽省宿州市靈璧縣

所用表結(jié)構(gòu)：

sql,server,樹形查詢,sqlserver遞歸查詢