无法在两个节点之间创建两个以上的相同关系 [英] unable to create more than 2 same relations between two nodes

问题描述

花了几天时间试图弄清楚为什么它不起作用.我的模型是Player-[:PLAYED_WITH_TEAM]->team-[:CONTESTED_IN]->league.这种关系的几个实例如下

Spent multiple days trying to figure out why this isn't working. My model is Player-[:PLAYED_WITH_TEAM]->team-[:CONTESTED_IN]->league. Few instances of this relation is as follows

bob-[:PLAYED_WITH_TEAM]->falcons-[:CONTESTED_IN]->ABC League
alice-[:PLAYED_WITH_TEAM]->falcons-[:CONTESTED_IN]->ABC League
bob-[:PLAYED_WITH_TEAM]->falcons-[:CONTESTED_IN]->XYZLeague

鲍勃在ABC和XYZ两个联赛中为同一支猎鹰"队效力.这是我要捕获的事实.由于鲍勃在2个不同的联赛中为同一支球队效力，因此我需要在相同的起点(Bob)和终点(Falcons)之间建立两个PLAYED_WITH_TEAM关系.

Bob played for the same team "Falcons" in two leagues ABC and XYZ. This is the fact i want to capture. Since Bob played for the same team in 2 different leagues, I need to have two PLAYED_WITH_TEAM relations between the same start (Bob) and end (Falcons) nodes.

我正在使用spring数据并已定义实体.我可以使用spring数据创建2个这样的关系，但最多可以创建2个这样的关系.也就是说，如果鲍勃在同一支猎鹰队效力过另一个第3联赛，那么我将无法建立第3关系.我不确定问题出在哪里.下面是我用于创建新关系的代码. PlayedWith是一个RelationshipEntity，其中Player作为开始节点，Team作为结束节点.

I am using spring data and have the entities defined. I am able to create 2 such relationships but not more than two using spring data. i.e. if bob played for the same team Falcons for another 3rd league, I am unable to create that 3rd relation. I am not sure where the problem is. Below is my code for creating the new relation. PlayedWith is a RelationshipEntity with Player as the start node and Team as the end node.

private PlayedWith createPlayedWithRelation(League currentLeague, Team team, Player p)
    {
        System.err.println("Creating PLAYED_WITH_TEAM relation between " + team + " and " + p + " and " + currentLeague);

        PlayedWith playedWith = template.createRelationshipBetween(p, team, PlayedWith.class, "PLAYED_WITH_TEAM", true);
        playedWith.setDuring(currentLeague.getStartDate());
        playedWith.setInLeague(currentLeague);
        playedWith.setPlayer(p);
        playedWith.setTeam(team);
        playedWith.setAsCaptain(p.isCaptain());

        team.addPlayer(p);
        template.save(playedWith);

        return playedWith;
    }

PlayedWith

PlayedWith

@RelationshipEntity (type = "PLAYED_WITH_TEAM")
public class PlayedWith
{
    @GraphId
    private Long nodeId;

    @StartNode
    Player player;

    @Fetch
    @EndNode
    Team team;
}

让我知道是否存在另一种存储此方案的方法.

Let me know if there is an alternate way of storing this scenario.

推荐答案

实际上，鲍勃和猎鹰之间只有一个:PLAYED_WITH_TEAM关系. 您确定要获取鲍勃和猎鹰之间的:PLAYED_WITH_TEAM关系数量正确吗?

Actually there should only be one :PLAYED_WITH_TEAM relationship between bob and the falcons. Are you sure that you query is right for getting the amount of :PLAYED_WITH_TEAM relationships between Bob and the falcons?

从SDN参考文档中:

注意

Spring Data Neo4j默认情况下确保只有一个 给定类型在任何两个给定实体之间的关系.这个可以 通过使用createRelationshipBetween()方法来规避 存储库或实体上的allowDuplicates参数.

Spring Data Neo4j ensures by default that there is only one relationship of a given type between any two given entities. This can be circumvented by using the createRelationshipBetween() method with the allowDuplicates parameter on repositories or entities.

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