Neo4j聚合函數

Question

我正在嘗試使用SUM函數並將其結果存儲爲關係的新屬性。但它不起作用。 我使用的查詢是：

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) 

我得到的錯誤是：

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)"

請解釋一下我做錯了。

Answer 1

試試：

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 

始終把聚集功能WITH或RETURN。