在列表的连续元素之间创建关系

Question

我正在尝试用neo4j cypher语言编写一个查询，该查询创建一个节点关系链，按特定条件排序。

例如。我有这个问题：

MATCH (n)
WHERE n.some_property = 'something'
WITH n
ORDER BY n.some_other_property
WITH collect(n) as node_list

我需要将node_list的每个元素与该列表的下一个元素相关联。

示例，如果node_list包含：

[a, b, c, d, e]

结果将是： CREATE (a)->[:rel]->(b)->[:rel]->(c)->[:rel]->(d)->[:rel]->(e)

所以最后的查询将是：

MATCH (n)
WHERE n.some_property = 'something'
WITH n
ORDER BY n.some_other_property
WITH collect(n) as node_list
CREATE LINKS OF CONSECUTIVE node_list

有什么办法吗？

Answer 1

是的！收集完成后，使用UNWIND获取一系列索引：

MATCH (n)
WHERE n.some_property = 'something'
WITH n
ORDER BY n.some_other_property
WITH COLLECT(n) as node_list
UNWIND RANGE(1, SIZE(node_list) - 1) AS idx
WITH node_list[idx - 1] AS from, node_list[idx] AS to
CREATE (from)-[:NEXT]->(to);