Neo4j 在附加条件下查找所有最短路径的查询不返回任何记录

我必须找到A和B之间具有附加属性的所有最短路径

此查询仅返回一条路由（如果是，则只有一条路由包含3个部分）：

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}

此路由的所有部分都将属性winter设置为true，但如果我想将此条件添加到查询中，则没有结果：

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

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我的问题是，为什么第二个查询即使在a和B之间有一条路由，也不会返回任何结果，这是最短的路由，并且该路由上的所有路径的属性winter都设置为true？

我相信您需要对路径进行另一次

匹配，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

将此形式化为答案

看起来您得到的是字符串属性而不是布尔属性。此条件应适用于您：

其中p.winter=“true”

如果要将这些属性更改为布尔属性，则需要匹配具有此属性的所有关系，并使用：

SET p.winter=（p.winter=“true”）
遗憾的是，您的查询没有返回任何结果。添加了第一个查询的结果，希望能对您有所帮助吗？
winter
是布尔属性还是字符串属性？如果您的条件是
其中p.winter=“true”
，您会得到结果吗？事实上，它是一个字符串属性！它与“”一起工作。。。
MATCH (darjeeling { name: 'Darjeeling' }), (sandakphu { name: 'Sandakphu' })
MATCH paths = allShortestPaths((darjeeling)-[*]-(sandakphu))
WHERE ALL (p IN relationships(paths) WHERE p.winter = true)
RETURN paths