Neo4j Java OGM帶鎖選擇

Question

我正在嘗試使用Java OGM for Neo4j鎖定最后一個節點的路徑。

為此，我編寫了以下查詢：

String q = "Match path = (p:Root) - [*1..100]-(m:Leaf) WHERE m.State = 'Non-Processed' WITH m,p,path ORDER BY length(path) Limit 1 SET m.State = 'Processing' RETURN path"

它通過鎖定最后一片葉子（通過更改其State屬性）來選擇必要的路徑。

但是，當我嘗試執行此查詢時：

session.query(Path.class, q, propertyMap)

我得到一個java.lang.RuntimeException: query() only allows read only cypher. To make modifications use execute() java.lang.RuntimeException: query() only allows read only cypher. To make modifications use execute()

正確的方法是什么？

Answer 1

您可能正在使用neo4j-ogm的舊版本，該版本對session.query（）有限制。 請升級到neo4j-ogm 1.1.4

Answer 2

找到了（可能不是最好的）解決方案。

String uid = UUID.randomUUID().toString();
String lockQuery = "Match path = (p:Root) - [*1..100]-(m:Leaf)"
   + "WHERE m.State = 'Non-Processed' "
   + "WITH m,p,path ORDER BY length(path) Limit 1 SET m.lock = " + uid
session.execute(lockQuery);
String getQuery = "Match path = (p:Root) - [*1..100]-(m:Leaf)"
   + "WHERE m.lock = " + uid + "RETURN path";
Path path = session.query(Path.class, getQuery, new Hashmap<String, Object>());

這樣行嗎？