Question

我正在使用Ne04j v3.1.0和Java驱动程序。我无法在显式事务中获取更新语句（cypher SET）的结果以保持不变。事务中的返回值显示更改，但在事务结束后，更改似乎已消失。我知道更新对结果处理很敏感

[http://neo4j.com/docs/developer-manual/current/drivers/process-results/][1]

所以我在代码中积极主动地使用了所有结果并关闭了我的会话。

我写了一个测试程序来演示这个问题：

package uk.co.scapps.createdirs.neo;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.neo4j.driver.v1.AuthTokens;
import org.neo4j.driver.v1.Driver;
import org.neo4j.driver.v1.GraphDatabase;
import org.neo4j.driver.v1.Record;
import org.neo4j.driver.v1.Session;
import org.neo4j.driver.v1.StatementResult;
import org.neo4j.driver.v1.Transaction;


public class Trans {
    static Driver driver = GraphDatabase.driver("bolt://localhost", AuthTokens.basic("neo4j", "neo4k"));
    static Session session = driver.session();
    final static Logger logger = LogManager.getLogger();

    public static void main(String[] args) {
        session = driver.session();
        StatementResult results ;
        session = driver.session();
        try (Transaction tx = session.beginTransaction()) {
            results = tx.run("MATCH (n:THING) RETURN n.name as name");
            while (results.hasNext()) {
                Record record = results.next();
                System.out.println("in the txn before the update: " + record.get("name").toString());
            }           
            results.consume();
            results = tx.run("MATCH (n:THING {name: 'a'}) SET n.name = 'asdasd' RETURN n.name as name");
            while (results.hasNext()) {
                Record record = results.next();
                System.out.println("results returned from the update: " + record.get("name").toString());
            }           
            results.consume();
            results = tx.run("MATCH (n:THING) RETURN n.name as name");
            while (results.hasNext()) {
                Record record = results.next();
                System.out.println("after the update but still in the txn: " + record.get("name").toString());
            }           
            results.consume();
            tx.close();
            session.close();
        }
        session = driver.session();
        results = session.run("MATCH (n:THING) RETURN n.name as name");
        while (results.hasNext()) {
            Record record = results.next();
            System.out.println("after the txn: " + record.get("name").toString());
        }           
        results.consume();
        session.close();
    }
}

这是输出：

in the txn before the update: "a"
in the txn before the update: "b"
in the txn before the update: "c"
results returned from the update: "asdasd"
after the update but still in the txn: "asdasd"
after the update but still in the txn: "b"
after the update but still in the txn: "c"
after the txn: "a"
after the txn: "b"
after the txn: "c"

我没有包含代码，但我编写了一个非事务性（隐式事务）版本的程序，它按预期工作。

我将不胜感激。

Answer 1

我未能执行txn.success()。

Neo4j Java驱动程序事务似乎不会提交

1 个答案: