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好吧,我试图在stackoverflow上找到一个适用于我的例子,但我无法找到它。我试图递归地连接每个节点的父节点在一个拥有父节点/子节点的表中。以下是我迄今为止:TSQL递归连接嵌套导航名称
CREATE TABLE #TBL_EXAMPLE (
PARENT_NAV_ID INT,
NAV_ID INT,
NAV_NAME VARCHAR(25)
)
INSERT INTO #TBL_EXAMPLE VALUES(NULL, 1, 'MILKY WAY')
INSERT INTO #TBL_EXAMPLE VALUES(1, 2, 'SOLAR SYSTEM')
INSERT INTO #TBL_EXAMPLE VALUES(3, 4, 'EARTH')
INSERT INTO #TBL_EXAMPLE VALUES(4, 5, 'ANTARCTICA')
; WITH #EXAMPLE_CTE AS (
SELECT
PARENT_NAV_ID,
NAV_ID,
NAV_NAME,
CAST('' AS VARCHAR(MAX)) AS NAV_PARENT_NAME
FROM #TBL_EXAMPLE
WHERE PARENT_NAV_ID IS NULL
UNION ALL
SELECT
EXMP.PARENT_NAV_ID,
EXMP.NAV_ID,
EXMP.NAV_NAME,
CT.NAV_PARENT_NAME + '/' + EXMP.NAV_NAME AS PARENT_NAV_NAME
FROM #TBL_EXAMPLE EXMP
INNER JOIN #EXAMPLE_CTE CT ON EXMP.PARENT_NAV_ID = CT.NAV_ID
)
SELECT
*
FROM #EXAMPLE_CTE
我得到的是这样的:
PARENT_NAV_ID NAV_ID NAV_NAME NAV_PARENT_NAME
NULL 1 MILKY WAY
1 2 SOLAR SYSTEM /SOLAR SYSTEM
我想这样什么:
PARENT_NAV_ID NAV_ID NAV_NAME NAV_PARENT_NAME
NULL 1 MILKY WAY MILKY WAY
1 2 SOLAR SYSTEM MILKY WAY/SOLAR SYSTEM
3 4 EARTH MILKY WAY/SOLAR SYSTEM/EARTH
4 5 ANTARCTICA MILKY WAY/SOLAR SYSTEM/EARTH/ANTARCTICA
我知道我缺少的一些基本认识CTE如何工作,但我遇到了一些让我明白的东西。任何帮助表示赞赏!
哇,我觉得愚蠢。谢谢! –
没关系,我添加了一个微小的编辑... – Shnugo
说实话:一个人能够写递归CTEs肯定是**不**:愚蠢:-)快乐的编码! – Shnugo