我在Sping Boot 中通过Neo4j查询实现CRUD操作时遇到了问题。
我的问题位于城市存储库、路线存储库、最短路径存储库和路线实体。
1）当我调用CityRepository的listAll和getById方法时，我得到了空城市名称，并在添加了如下所示的路线后列出了它的路线。

[
    {
        "id": "077d1b16-9a4b-4fb0-947b-52031774d949",
        "name": "London",
        "routes": []
    },
    {
        "id": "077d1b16-9a4b-4fb0-947b-52031774d949",
        "name": null,
        "routes": [
            {
                "id": "6db5dd3f-085a-4d50-b025-4f0bee847fcf",
                "from": "London",
                "destination": "Berlin",
                "departureTime": "9:00",
                "arriveTime": "11:30",
                "duration": 2.5
            }
        ]
    }
]

2）（编辑）添加City的任意一条路线，调用City的listAll后，得到截图中的这个结果。
第一次
下面是我的项目链接：Project
下面是 Postman 请求的集合：Link
以下是与我的问题相关的屏幕截图：Link
如何解决我的问题？
以下是我的实体，如下面所示的城市和路线。

城市

public class City {

    @Id
    @Property
    private UUID id;

    @Property
    private String name;

    @Relationship(type = "ROUTES", direction = Relationship.Direction.OUTGOING)
    private Set<Route> routes = new HashSet<>();

    public City(String name) {
        this.name = name;
    }
}

路线

public class Route {

    @Id
    @Property
    private UUID id;

    @Property
    private String from;

    @Property
    private String destination;

    @Property
    private String departureTime;

    @Property
    private String arriveTime;

    @Property
    private Double duration;
}

这是我的CityRepository，如下所示。

public interface CityRepository extends Neo4jRepository<City,UUID> {

    @Query("MATCH (city:City) OPTIONAL MATCH (city)-[r:ROUTES]->(route:Route) RETURN city, collect(r), collect(route)")
    List<City> listAll();

    @Query("MATCH (city:City {id: $cityId}) OPTIONAL MATCH (city)-[r:ROUTES]->(route:Route) RETURN city, collect(r), collect(route)")
    City getById(UUID cityId);

    @Query("MATCH (city:City {name: $cityName}) RETURN city")
    City getByCityName(String cityName);

    @Query("CREATE (city:City {id: randomUUID(), name: $cityName}) RETURN city")
    City saveCity(String cityName);

    @Query("MATCH (city:City {id: $cityId}) SET city.name = $cityName RETURN city")
    City updateCity(UUID cityId, String cityName);

    @Query("MATCH (city:City {id: $cityId}) DELETE city")
    void deleteCity(UUID cityId);
}

下面显示的是我的RouteRepository。

public interface RouteRepository extends Neo4jRepository<Route,UUID> {

    @Query("MATCH (city:City {id: $cityId})-[:ROUTES]->(route:Route) RETURN route")
    List<Route> listAllByCityId(UUID cityId);

    @Query("MATCH (route:Route {id: $routeId}) RETURN route")
    Route getById(UUID routeId);

    @Query("CREATE (city:City {id: $cityId})-[:ROUTES]->(route:Route {id: randomUUID(), from: $from, destination: $destination, departureTime: $departureTime," +
            "arriveTime: $arriveTime, duration: $duration}) " +
            "RETURN route")
    Route saveRoute(UUID cityId, String from, String destination, String departureTime,
                    String arriveTime, double duration);

    @Query("MATCH (city:City {id: $cityId})-[:ROUTES]->(route:Route {id: $routeId}) " +
            "SET route.from = $from, route.destination = $destination,route.departureTime = $departureTime," +
            "route.arriveTime = $arriveTime, route.duration = $duration RETURN route")
    Route updateRoute(UUID cityId, UUID routeId, String from, String destination,String departureTime,
                      String arriveTime,double duration);

    @Query("MATCH (city:City {id: $cityId})-[r:ROUTES]->(route:Route {id: $routeId}) DELETE r, route")
    void deleteRoute(UUID cityId, UUID routeId);
}