Question

我有一个现有的Neo4查询，以带回用户兴趣，以及这些兴趣是否相关。查询是：

MATCH (u:User)-[r1:INTERESTED_IN]-(i1:Interest)
WHERE u.emailAddress = 'bob@mail.com'
OPTIONAL MATCH (u)-[r2:INTERESTED_IN]-(i2:Interest)
OPTIONAL MATCH (i1)-[r3:RELATED_TO]-(i2)
RETURN u, r1, i1, r2, i2, r3

这将映射为Spring Data Neo4J存储库方法，如下所示：

User findInterestsByEmailAddressIgnoreCase(@Param("emailAddress") String emailAddress);

我想扩展图形，以便用户可以认识其他用户（例如bob认识fred和tom以及fred和tom彼此也知道）。如何修改相同的查询以同时恢复这些关系？

我尝试为认识另一个用户的用户添加可选匹配，如下所示：

MATCH (u:User)-[r1:INTERESTED_IN]-(i1:Interest)
WHERE u.emailAddress = 'bob@mail.com'
OPTIONAL MATCH (u)-[r2:INTERESTED_IN]-(i2:Interest)
OPTIONAL MATCH (i1)-[r3:RELATED_TO]-(i2)
OPTIONAL MATCH (u:User)-[r5:KNOWS]-(u2:User)
RETURN u, r1, i1, r2, i2, r3, r5, u2

这似乎可以运行并带回neo4j浏览器中的图形，但是Spring Data似乎因错误而失败

org.springframework.dao.IncorrectResultSizeDataAccessException：结果大小不正确：最多为1 在org.springframework.data.neo4j.repository.query.GraphQueryExecution $ SingleEntityExecution.execute（GraphQueryExecution.java:83）

我需要在查询中更改的任何指针吗？

更新

用户类别

@NodeEntity
public class User {

@Id
@GeneratedValue
private Long id;

public Long getId() {
    return id;
}

@Index(unique = true)
private String emailAddress;

private String name;

@Relationship(type = "INTERESTED_IN", direction = Relationship.OUTGOING)
private Set<UserInterest> interests = new HashSet<>();

public Set<UserInterest> getInterests() {
    return interests;
}

public void setInterests(Set<UserInterest> interests) {
    this.interests = interests;
}

@Relationship(type = "KNOWS", direction = Relationship.UNDIRECTED)
private Set<RelatedUser> relatedUsers = new HashSet<>();

public Set<RelatedUser> getRelatedUsers() {
    return relatedUsers;
}

public void setRelatedUsers(Set<RelatedUser> relatedUsers) {
    this.relatedUsers = relatedUsers;
}

... additional getters/setters

}

Answer 1

根据Spring-data-neo4j docs，正确的方法签名是

 BookAdapter adapter = new BookAdapter(getActivity(), R.layout.list_item, Library.getInstance().getBible(bible).getBook(pos).getChapters());
    setListAdapter(adapter);
    getListView().setOnItemClickListener(this);

Neo4J查询可带回用户兴趣和其他已知用户

1 个答案: