Question

我需要从Neo4j中的不同起始节点查询多个路径（在UI中绘制）（可能是数百条路径），我正在使用UNION来组合查询，但我怀疑它不是检索数据的最有效方法（我也在启动节点上使用索引）。在创建大型查询时，会发生各种令人讨厌的事情。

查询看起来像这样：

MATCH path = ((n:actor)-[*0..2]->(g)-[p:was_filmed_at]->(k:movie_set)-[l:located]->(i:state)) 
WHERE n.name=’john doe1' AND (g:acted_in OR g:produced) 
AND p.addDate >= '2017-12-10T00:00:00+00:00' 
AND p.addDate <= '2017-12-12T08:08:06+00:00' 
AND l.addDate >= '2017-12-10T00:00:00+00:00' 
AND l.addDate <= '2017-12-12T08:08:06+00:00' 
RETURN nodes(path), relationships(path) 
LIMIT 1000

UNION 

MATCH path = ((n:actor)-[*0..2]->(g)-[p:was_filmed_at]->(k:movie_set)-[l:located]->(i:state)) 
WHERE n.name=’john doe2' AND (g:acted_in OR g:produced) 
AND p.addDate >= '2017-12-10T00:00:00+00:00' 
AND p.addDate <= '2017-12-12T08:08:06+00:00' 
AND l.addDate >= '2017-12-10T00:00:00+00:00' 
AND l.addDate <= '2017-12-12T08:08:06+00:00' 
RETURN nodes(path), relationships(path) 
LIMIT 1000

UNION 

MATCH path = ((n:actor)-[*0..2]->(g)-[p:was_filmed_at]->(k:movie_set)-[l:located]->(i:state)) 
WHERE n.name=’john doe3' AND (g:acted_in OR g:produced) 
AND p.addDate >= '2017-12-10T00:00:00+00:00' 
AND p.addDate <= '2017-12-12T08:08:06+00:00' 
AND l.addDate >= '2017-12-10T00:00:00+00:00' 
AND l.addDate <= '2017-12-12T08:08:06+00:00' 
RETURN nodes(path), relationships(path) 
LIMIT 1000

这是一个只有3条路径的查询，它不能很好地扩展到数百个路径。有没有一种简单，更有效的方法来做到这一点？

Answer 1

由于您只更改n.name比较，因此可以使用IN operator重写查询，并将名称列表作为数组传递。这样：

MATCH path = ((n:actor)-[*0..2]->(g)-[p:was_filmed_at]->(k:movie_set)-[l:located]->(i:state))
WHERE n.name IN ['john doe1', 'john doe2', 'john doe3']
AND (g:acted_in OR g:produced)
AND '2017-12-10T00:00:00+00:00' <= p.addDate <= '2017-12-12T08:08:06+00:00'
AND '2017-12-10T00:00:00+00:00' <= l.addDate <= '2017-12-12T08:08:06+00:00'
RETURN nodes(path), relationships(path)
LIMIT 1000

你也可以将不平等链接起来：AND '2017-12-10T00:00:00+00:00' <= p.addDate <= '2017-12-12T08:08:06+00:00'。确保:actor(name)上有an index，以便快速索引查找起始节点。 （感谢@InverseFalcon）

Neo4j Cypher：使用UNION创建非常大的查询

1 个答案: