Neo4j聚合函数

Question

我正在尝试使用SUM函数并将其结果存储为关系的新属性。但它不起作用。 我使用的查询是：

MATCH (a:Employee)-[r:CorporateMessage]->(b) 
WHERE a.Eid = 6001 AND b.Eid IN [6002,6003,6004,6005,5001] 
SET r.Internalsum = SUM(r.Count) 

我得到的错误是：

Invalid use of aggregating function sum(...) in this context (line 1, column 124 (offset: 123)) "MATCH (a:Employee)-[r:CorporateMessage]->(b)WHERE a.Eid = 6001 AND b.Eid IN [6002,6003,6004,6005,5001] SET r.Internalsum = SUM(r.Count)"

请解释一下我做错了。

Answer 1

试试：

MATCH (a:Employee)-[r:CorporateMessage]->(b) 
WHERE a.Eid = 6001 AND b.Eid IN [6002,6003,6004,6005,5001] 
WITH r, SUM(r.count) as count 
SET r.Internalsum = count 

始终把聚集功能WITH或RETURN。