Question

我想要像Cypher一样，

OPTIONAL MATCH (a1:Article) WHERE a1.status='active'
WITH collect(a1) as a1_col
OPTIONAL MATCH (a2:Article) WHERE a2.category='xyz'
WITH DISTINCT a1_col + collect(a2) as a
MATCH (a)-[:author]->(u:User)
WHERE NOT id(u)=101
RETURN a

我在这个密码中遇到Type mismatch: a already defined with conflicting type List<Node>错误，对此的任何帮助都将非常感激。我需要OPTIONAL_MATCH和MATCH子句在这里分开。

Answer 1

变量a是List<Node>，您可以在MATCH子句中将其用作Node。

您应该使用此查询：

OPTIONAL MATCH (a1:Article) WHERE a1.status='active'
WITH collect(a1) as a1_col
OPTIONAL MATCH (a2:Article) WHERE a2.category='xyz'
WITH DISTINCT a1_col + collect(a2) as a
MATCH (article)-[:author]->(u:User)
WHERE NOT id(u)=101 AND article IN a
RETURN a

我认为您可以像这样优化查询：

MATCH (u:User) WHERE id(u)=101 WITH u
MATCH (a:Article)
WHERE (a.category='xyz' OR a.status='active') AND
      NOT (a)-[:author]->(u)
RETURN collect(DISTINCT a)

Cypher Assistance，将两个可选匹配与匹配相结合

1 个答案: