Question

我必须找到A和B之间的所有最短路径以及附加属性。

此查询只返回一条路线（这是真的，只有一条路线有3部分）：

MATCH (darjeeling { name: 'Darjeeling' }),(sandakphu { name: 'Sandakphu' }), 
    paths = allShortestPaths((darjeeling)-[*]-(sandakphu))
RETURN paths

结果：

{"start":{"identity":1,"labels":["town"],"properties":{"name":"Darjeeling"}},"end":{"identity":3,"labels":["peak"],"properties":{"altitude":"12400 ft","name":"Sandakphu"}},"segments":[{"start":{"identity":1,"labels":["town"],"properties":{"name":"Darjeeling"}},"relationship":{"identity":2,"start":1,"end":0,"type":"trek","properties":{"distance":15,"name":"Darjeeling-Rimbik","winter":"true","summer":"true"}},"end":{"identity":0,"labels":["town"],"properties":{"name":"Rimbik"}}},{"start":{"identity":0,"labels":["town"],"properties":{"name":"Rimbik"}},"relationship":{"identity":3,"start":0,"end":2,"type":"trek","properties":{"distance":18,"name":"Rimbik-BhikeBhanja","winter":"true","summer":"true"}},"end":{"identity":2,"labels":["village"],"properties":{"name":"BhikeBhanja"}}},{"start":{"identity":2,"labels":["village"],"properties":{"name":"BhikeBhanja"}},"relationship":{"identity":4,"start":2,"end":3,"type":"trek","properties":{"distance":4,"name":"BhikeBhanja-Sandakphu","winter":"true","summer":"true"}},"end":{"identity":3,"labels":["peak"],"properties":{"altitude":"12400 ft","name":"Sandakphu"}}}],"length":3}

此路线的所有部分都将属性冬季设置为true，但如果我想在查询中添加此类条件，则无效：

MATCH (darjeeling { name: 'Darjeeling' }),(sandakphu { name: 'Sandakphu' }), 
    paths = allShortestPaths((darjeeling)-[*]-(sandakphu))
WHERE ALL (p IN relationships(paths) WHERE p.winter = true)
RETURN paths

我的问题是，为什么第二个查询没有返回结果，即使A和B之间有路由，这是最短路径，并且此路由上的所有路径都将属性winter设置为true？

Answer 1

将此形式化为答案。

看起来你有字符串属性而不是布尔属性。这种情况对您有用：

WHERE p.winter = "true"

如果要将这些更改为布尔属性，则需要匹配与此属性的所有关系并使用：

SET p.winter = (p.winter = "true")

Answer 2

我相信你需要为路径做另一个MATCH，如下所示：

MATCH (darjeeling { name: 'Darjeeling' }), (sandakphu { name: 'Sandakphu' })
MATCH paths = allShortestPaths((darjeeling)-[*]-(sandakphu))
WHERE ALL (p IN relationships(paths) WHERE p.winter = true)
RETURN paths

查找具有附加条件的所有最短路径的查询不返回任何记录

2 个答案: