不能作出減少暗號

Question

工作在這個暗號查詢，我要總結所有的權重超過路徑中的圖形：

MATCH p=(n:person)-[r*2..3]->(m:person) 
WHERE n.name = 'alice' and m.name = 'bob' 
WITH REDUCE(weights=0, rel IN r : weights + rel.weight) AS weight_sum, p 
return n.name, m.name, weight_sum 
LIMIT 10 

在此查詢，我期望得到一個表3列： n.name，m.name（在所有行中相同）和weight_sum - 根據特定路徑中的權重和。 不過，我得到這個錯誤：

reduce(...) requires '| expression' (an accumulation expression) (line 3, 
column 6 (offset: 89)) 
"WITH REDUCE(weights=0, rel IN r : weights + rel.weight) AS weight_sum, p" 

我顯然錯過一些小事。但是什麼？

Answer 1

不應認爲是

REDUCE(weights=0, rel IN r | weights + rel.weight) AS weight_sum 

（具有管代替結腸），按照在http://neo4j.com/docs/developer-manual/current/cypher/functions/list/的文件？

reduce(totalAge = 0, n IN nodes(p)| totalAge + n.age) AS reduction 

希望這會有所幫助。

Regards， Tom