Neo4j 如何使用或匹配节点标签?
如何在这样的查询中匹配两个可能的节点标签 根据赛博萨姆的建议,我改为:Neo4j 如何使用或匹配节点标签?,neo4j,cypher,Neo4j,Cypher,如何在这样的查询中匹配两个可能的节点标签 根据赛博萨姆的建议,我改为: match (p:Product {id:'5116003'})-[r]->(o:Attributes|ExtraAttribute) return p, o 现在我需要添加第二个where子句。如何修改它?您可以尝试使用以下函数: MATCH (p:Product {id:'5116003'})-[r]->(o) WHERE o:Attributes OR o:ExtraAttributes **WHERE
match (p:Product {id:'5116003'})-[r]->(o:Attributes|ExtraAttribute) return p, o
现在我需要添加第二个where子句。如何修改它?您可以尝试使用以下函数:
MATCH (p:Product {id:'5116003'})-[r]->(o)
WHERE o:Attributes OR o:ExtraAttributes
**WHERE any(key in keys(o) WHERE toLower(key) contains 'weight')**
return o
此外,如果有,您可以使用apoc.path.expand path expander过程,该过程根据标签过滤器从最小到最大的给定关系从开始节点展开
match (p:Product {id:'5116003'})-[r]->(o)
where any (label in labels(o) where label in ['Attributes', 'ExtraAttribute'])
return p, o
.查询的这两种单标签形式:
match (p:Product {id:'5116003'})
call apoc.path.expand(p, null,"+Attributes|ExtraAttribute",0,1) yield path
with nodes(path) as nodes
// return p and o nodes
return nodes[0], nodes[1]
生成相同的执行计划,如下所示。我假设:Productid上有一个索引:
这是上面第二个查询的两个标签形式:
+-----------------+----------------+------+---------+------------------+--------------+
| Operator | Estimated Rows | Rows | DB Hits | Variables | Other |
+-----------------+----------------+------+---------+------------------+--------------+
| +ProduceResults | 0 | 0 | 0 | o, p | p, o |
| | +----------------+------+---------+------------------+--------------+
| +Filter | 0 | 0 | 0 | anon[33], o, p | o:Attributes |
| | +----------------+------+---------+------------------+--------------+
| +Expand(All) | 0 | 0 | 0 | anon[33], o -- p | (p)-->(o) |
| | +----------------+------+---------+------------------+--------------+
| +NodeIndexSeek | 0 | 0 | 1 | p | :Product(id) |
+-----------------+----------------+------+---------+------------------+--------------+
生成一个非常相似的执行计划,因此成本可能不会太高:
MATCH (p:Product {id:'5116003'})-->(o) WHERE o:Attributes OR o: ExtraAttribute RETURN p, o;
顺便说一句,@BrunoPeres的答案中的第一个查询也有类似的执行计划,但是过滤操作非常不同。现在还不清楚哪一个会更快
[更新]
要回答您更新的问题:由于您不能有2个背对背的WHERE子句,您只需在现有WHERE子句中添加更多术语,如下所示:
+-----------------+----------------+------+---------+------------------+-------------------------------------+
| Operator | Estimated Rows | Rows | DB Hits | Variables | Other |
+-----------------+----------------+------+---------+------------------+-------------------------------------+
| +ProduceResults | 0 | 0 | 0 | o, p | p, o |
| | +----------------+------+---------+------------------+-------------------------------------+
| +Filter | 0 | 0 | 0 | anon[33], o, p | Ors(o:Attributes, o:ExtraAttribute) |
| | +----------------+------+---------+------------------+-------------------------------------+
| +Expand(All) | 0 | 0 | 0 | anon[33], o -- p | (p)-->(o) |
| | +----------------+------+---------+------------------+-------------------------------------+
| +NodeIndexSeek | 0 | 0 | 1 | p | :Product(id) |
+-----------------+----------------+------+---------+------------------+-------------------------------------+
第二种似乎更有效。“路径”返回什么?是否可以直接返回“o”节点?@user697911 return path返回整个路径。要返回p和o,请查看我的编辑。我当前的查询有很多这样的约束:其中,keyso中的任意键toLowerkey包含“+attrKey+”,其中attrKey或attrValue是变量。是否可以使用“apoc”向上述查询添加类似的约束?@user697911我不这么认为,因为路径扩展器仅基于标签和关系类型工作。但我认为这是一个好问题。也许你应该提出一个新的问题。。。
+-----------------+----------------+------+---------+------------------+-------------------------------------+
| Operator | Estimated Rows | Rows | DB Hits | Variables | Other |
+-----------------+----------------+------+---------+------------------+-------------------------------------+
| +ProduceResults | 0 | 0 | 0 | o, p | p, o |
| | +----------------+------+---------+------------------+-------------------------------------+
| +Filter | 0 | 0 | 0 | anon[33], o, p | Ors(o:Attributes, o:ExtraAttribute) |
| | +----------------+------+---------+------------------+-------------------------------------+
| +Expand(All) | 0 | 0 | 0 | anon[33], o -- p | (p)-->(o) |
| | +----------------+------+---------+------------------+-------------------------------------+
| +NodeIndexSeek | 0 | 0 | 1 | p | :Product(id) |
+-----------------+----------------+------+---------+------------------+-------------------------------------+
MATCH (p:Product {id:'5116003'})-[r]->(o)
WHERE
(o:Attributes OR o:ExtraAttributes) AND
ANY(key in KEYS(o) WHERE TOLOWER(key) CONTAINS 'weight')
RETURN o;