表t1有两列 f1 表示站点编号 f2 表示与它相通的站点编号
列f1 列f2
A B
A F
A G
B C
B G
B H
B A
C B
C H
C I
C D
D C
D I
D J
E J
E D
F A
F G
G A
G B
G H
G F
H G
H B
H C
H I
I H
I C
I D
I F
F I
F D
F E现在如果我想查找 从A到 I怎么走路线,,应该会有多条路线, 想通过sql来实现查找方式,不知道可有好的方法。
列f1 列f2
A B
A F
A G
B C
B G
B H
B A
C B
C H
C I
C D
D C
D I
D J
E J
E D
F A
F G
G A
G B
G H
G F
H G
H B
H C
H I
I H
I C
I D
I F
F I
F D
F E现在如果我想查找 从A到 I怎么走路线,,应该会有多条路线, 想通过sql来实现查找方式,不知道可有好的方法。
if object_id('[TB]') is not null drop table [TB]
GO
create table [TB]([f1] varchar(1),[f2] varchar(1))
insert [TB]
select 'A','B' union all
select 'A','F' union all
select 'A','G' union all
select 'B','C' union all
select 'B','G' union all
select 'B','H' union all
select 'B','A' union all
select 'C','B' union all
select 'C','H' union all
select 'C','I' union all
select 'C','D' union all
select 'D','C' union all
select 'D','I' union all
select 'D','J' union all
select 'E','J' union all
select 'E','D' union all
select 'F','A' union all
select 'F','G' union all
select 'G','A' union all
select 'G','B' union all
select 'G','H' union all
select 'G','F' union all
select 'H','G' union all
select 'H','B' union all
select 'H','C' union all
select 'H','I' union all
select 'I','H' union all
select 'I','C' union all
select 'I','D' union all
select 'I','F' union all
select 'F','I' union all
select 'F','D' union all
select 'F','E'DECLARE @start VARCHAR(10),@end VARCHAR(10)
SET @start='A'
SET @end='I'IF OBJECT_ID('tempdb..#temp') IS NOT NULL
DROP TABLE #tempCREATE TABLE #temp(
way VARCHAR(MAX),
f1 VARCHAR(10),
f2 VARCHAR(10),
flag int)
INSERT INTO #temp
SELECT ','+f1+','+f2,f1,f2,0 FROM tb WHERE f1=@startWHILE (SELECT COUNT(1) FROM #temp WHERE flag=0)>0
BEGIN
DECLARE @i VARCHAR(10),@j VARCHAR(MAX)
SELECT TOP 1 @i=f2,@j=way FROM #temp WHERE flag=0
UPDATE #temp SET flag = 1 WHERE f2=@i
INSERT INTO #temp
SELECT @j+','+f2,f1,f2,0 FROM TB t WHERE f1=@i AND f2 NOT IN (SELECT f1 FROM #temp)
ENDSELECT STUFF(way,1,1,'') FROM #temp WHERE RIGHT(way,LEN(@end))=@end/*
A,F,I
A,B,C,I
A,B,H,I
*/DROP TABLE #tempdrop table [TB]
最后三条我写错了
不是
F I
F D
F E
应该是
J I
J D
J E我测试了一下,这种方式可以查找出路径,但好像不全啊。
if object_id('[TB]') is not null drop table [TB]
GO
create table [TB]([f1] varchar(1),[f2] varchar(1))
insert [TB]
select 'A','B' union all
select 'A','F' union all
select 'A','G' union all
select 'B','C' union all
select 'B','G' union all
select 'B','H' union all
select 'B','A' union all
select 'C','B' union all
select 'C','H' union all
select 'C','I' union all
select 'C','D' union all
select 'D','C' union all
select 'D','I' union all
select 'D','J' union all
select 'E','J' union all
select 'E','D' union all
select 'F','A' union all
select 'F','G' union all
select 'G','A' union all
select 'G','B' union all
select 'G','H' union all
select 'G','F' union all
select 'H','G' union all
select 'H','B' union all
select 'H','C' union all
select 'H','I' union all
select 'I','H' union all
select 'I','C' union all
select 'I','D' union all
select 'I','F' union all
select 'J','I' union all
select 'J','D' union all
select 'J','E'DECLARE @start VARCHAR(10),@end VARCHAR(10)
SET @start='A'
SET @end='I'IF OBJECT_ID('tempdb..#temp') IS NOT NULL
DROP TABLE #tempCREATE TABLE #temp(
way VARCHAR(MAX),
f1 VARCHAR(10),
f2 VARCHAR(10),
flag int)
INSERT INTO #temp
SELECT '-'+f1+'-'+f2,f1,f2,0 FROM tb WHERE f1=@startWHILE (SELECT COUNT(1) FROM #temp WHERE flag=0)>0
BEGIN
DECLARE @i VARCHAR(10),@j VARCHAR(MAX)
SELECT TOP 1 @i=f2,@j=way FROM #temp WHERE flag=0
UPDATE #temp SET flag = 1 WHERE f2=@i
INSERT INTO #temp
SELECT @j+'-'+f2,f1,f2,0 FROM TB t WHERE f1=@i AND f2 NOT IN (SELECT f1 FROM #temp WHERE way<@j)
ENDSELECT STUFF(way,1,1,'') FROM #temp WHERE RIGHT(way,LEN(@end))=@end/*
A-B-C-I
A-B-H-I
A-B-C-D-I
A-B-C-D-C-I
A-B-C-D-C-H-I
A-B-C-D-C-D-I
A-B-C-D-C-D-J-I
A-B-C-D-C-H-I-H-I
A-B-C-D-C-D-J-I-H-I
A-B-C-D-C-D-J-E-J-I
*/DROP TABLE #tempdrop table [TB]
SET @start='A'
SET @end='I'IF OBJECT_ID('tempdb..#temp') IS NOT NULL
DROP TABLE #tempCREATE TABLE #temp(
way VARCHAR(MAX),
f1 VARCHAR(10),
f2 VARCHAR(10),
flag int)
INSERT INTO #temp
SELECT '-'+f1+'-'+f2,f1,f2,0 FROM tb WHERE f1=@startWHILE (SELECT COUNT(1) FROM #temp WHERE flag=0)>0
BEGIN
DECLARE @i VARCHAR(10),@j VARCHAR(MAX)
SELECT TOP 1 @i=f2,@j=way FROM #temp WHERE flag=0
UPDATE #temp SET flag = 1 WHERE f2=@i
INSERT INTO #temp
SELECT @j+'-'+f2,f1,f2,0 FROM TB t WHERE f1=@i AND f2 NOT IN (SELECT f1 FROM #temp WHERE way<=@j)
ENDSELECT STUFF(way,1,1,'') FROM #temp WHERE RIGHT(way,LEN(@end))=@end/*
A-B-C-I
A-B-H-I
A-B-C-D-I
*/DROP TABLE #temp
A-G-H-I
A-F-G-H-I
insert #y
select 'A','B' union all
select 'A','F' union all
select 'A','G' union all
select 'B','C' union all
select 'B','G' union all
select 'B','H' union all
select 'B','A' union all
select 'C','B' union all
select 'C','H' union all
select 'C','I' union all
select 'C','D' union all
select 'D','C' union all
select 'D','I' union all
select 'D','J' union all
select 'E','J' union all
select 'E','D' union all
select 'F','A' union all
select 'F','G' union all
select 'G','A' union all
select 'G','B' union all
select 'G','H' union all
select 'G','F' union all
select 'H','G' union all
select 'H','B' union all
select 'H','C' union all
select 'H','I' union all
select 'I','H' union all
select 'I','C' union all
select 'I','D' union all
select 'I','F' union all
select 'J','I' union all
select 'J','D' union all
select 'J','E'
GO
WITH tb_a AS(
SELECT #y.f1,#y.f2,[result]=CAST(#y.f1 +'->' + #y.f2 AS VARCHAR(1500)) FROM #y WHERE #y.f1='a'
UNION ALL
SELECT #y.f1,#y.f2,[result]=CAST([result]+ '->' + #y.f2 AS VARCHAR(1500)) FROM tb_a a INNER JOIN #y ON a.f2=#y.f1 WHERE charIndex(#y.f2,a.[result])<1
)
SELECT * FROM tb_a WHERE result LIKE '%i'
GO
-->生成表t1
if object_id('t1') is not null
drop table t1
Go
Create table t1([f1] nvarchar(1),[f2] nvarchar(1))
Insert into t1
Select N'A',N'B'
Union all Select N'A',N'F'
Union all Select N'A',N'G'
Union all Select N'B',N'C'
Union all Select N'B',N'G'
Union all Select N'B',N'H'
Union all Select N'B',N'A'
Union all Select N'C',N'B'
Union all Select N'C',N'H'
Union all Select N'C',N'I'
Union all Select N'C',N'D'
Union all Select N'D',N'C'
Union all Select N'D',N'I'
Union all Select N'D',N'J'
Union all Select N'E',N'J'
Union all Select N'E',N'D'
Union all Select N'F',N'A'
Union all Select N'F',N'G'
Union all Select N'G',N'A'
Union all Select N'G',N'B'
Union all Select N'G',N'H'
Union all Select N'G',N'F'
Union all Select N'H',N'G'
Union all Select N'H',N'B'
Union all Select N'H',N'C'
Union all Select N'H',N'I'
Union all Select N'I',N'H'
Union all Select N'I',N'C'
Union all Select N'I',N'D'
Union all Select N'I',N'F'
Union all Select N'J',N'I'
Union all Select N'J',N'D'
Union all Select N'J',N'E'DECLARE @startPoint NVARCHAR(1),@endPoint NVARCHAR(1)SELECT @startPoint='A',@endPoint='I'
IF object_id('tempdb..#Result')IS NOT NULL
DROP TABLE #Result
;WITH c1 AS (
SELECT
0 AS Row
,f1 AS startPoint
,f2 AS endPoint
,CONVERT(NVARCHAR(max),f1+' - >'+f2) AS Route
FROM t1
UNION ALL
SELECT
b.Row+1
,b.startPoint
,a.f2
,CONVERT(NVARCHAR(MAX),b.Route+' - >'+a.f2)
FROM t1 AS a
INNER JOIN c1 AS b ON a.f1=b.endPoint
WHERE CHARINDEX(a.f2,b.Route)=0
)
SELECT
Row+2 AS 步數
,startPoint AS 始點
,endPoint AS 終點
,Route AS 路線
INTO #Result
FROM c1
WHERE startPoint=@startPoint
AND endPoint=@endPoint
ORDER BY 步數
OPTION (MAXRECURSION 0)
SELECT
a.步數
,a.始點
,a.終點
,a.路線
,CONVERT(BIT,CASE WHEN NOT EXISTS(SELECT 1 FROM #Result AS x
WHERE x.步數<a.步數
)
THEN 1
ELSE 0
END) AS 是否最佳路線
FROM #Result AS a
/*
步數 始點 終點 路線 是否最佳路線
----------- ---- ---- ------------------------------------------ -------------
4 A I A - >G - >H - >I 1
4 A I A - >B - >H - >I 1
4 A I A - >B - >C - >I 1
5 A I A - >B - >C - >D - >I 0
5 A I A - >B - >C - >H - >I 0
5 A I A - >B - >H - >C - >I 0
5 A I A - >B - >G - >H - >I 0
5 A I A - >G - >H - >C - >I 0
5 A I A - >G - >B - >H - >I 0
5 A I A - >G - >B - >C - >I 0
5 A I A - >F - >G - >H - >I 0
6 A I A - >F - >G - >H - >C - >I 0
6 A I A - >G - >B - >C - >D - >I 0
6 A I A - >G - >H - >B - >C - >I 0
6 A I A - >G - >B - >H - >C - >I 0
6 A I A - >G - >H - >C - >D - >I 0
6 A I A - >B - >G - >H - >C - >I 0
6 A I A - >B - >H - >C - >D - >I 0
6 A I A - >F - >G - >B - >H - >I 0
6 A I A - >F - >G - >B - >C - >I 0
6 A I A - >B - >C - >D - >J - >I 0
6 A I A - >G - >B - >C - >H - >I 0
7 A I A - >F - >G - >B - >C - >H - >I 0
7 A I A - >F - >G - >B - >C - >D - >I 0
7 A I A - >F - >G - >H - >B - >C - >I 0
7 A I A - >F - >G - >B - >H - >C - >I 0
7 A I A - >B - >H - >C - >D - >J - >I 0
7 A I A - >B - >G - >H - >C - >D - >I 0
7 A I A - >G - >H - >C - >D - >J - >I 0
7 A I A - >G - >B - >H - >C - >D - >I 0
7 A I A - >G - >H - >B - >C - >D - >I 0
7 A I A - >G - >B - >C - >D - >J - >I 0
7 A I A - >F - >G - >H - >C - >D - >I 0
8 A I A - >F - >G - >H - >C - >D - >J - >I 0
8 A I A - >G - >H - >B - >C - >D - >J - >I 0
8 A I A - >G - >B - >H - >C - >D - >J - >I 0
8 A I A - >B - >G - >H - >C - >D - >J - >I 0
8 A I A - >F - >G - >B - >H - >C - >D - >I 0
8 A I A - >F - >G - >H - >B - >C - >D - >I 0
8 A I A - >F - >G - >B - >C - >D - >J - >I 0
9 A I A - >F - >G - >H - >B - >C - >D - >J - >I 0
9 A I A - >F - >G - >B - >H - >C - >D - >J - >I 0
*/