neo4j - 在列表的连续元素之间创建关系

Question

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

例如。我有这个查询:

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链接起来。

例如，如果 node_list 包含:

[a, b, c, d, e]

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

所以最终的查询将是:

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!拥有收藏后，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);