Question

我遇到了需要使用neo4jClient将Neo4j中的分层对象Graph加载到C＃中的情况

我在C＃中有一个帖子类作为休闲：

public class Post : BaseNode
{
    public Post Parent { get; set; }
    public float Id { get; set; }
    public string Text { get; set; }
    public ICollection<HashTag> HashTags { get; set; }
    public ICollection<IKeyCommand> KeyTags { get; set; }
    public ICollection<NeoDateTime> DueDates { get; set; }
    public IdentityUser Author { get; set; }
    public ICollection<IdentityUser> MentionedUsers { get; set; }
    public ICollection<Team> MentionedTeam { get; set; }
    public ICollection<PostAttachment> Attachments { get; set; }
    public string Priority { get; set; }

}

这是我的图表： ThePost Graph

现在想象一个方法需要使用父ID

加载图表的所有父项及其所有相关属性

我已经提出了这个产生所需Cypher的C＃代码：

public IList<Post> LoadParents(int id)
    {
        var matchStringTemplate = "(post:Post {{Id:{0}}})-[r:HAS_Parent*]->(parents:Post)";
        var matchString = string.Format(matchStringTemplate, id);

        var q = new CypherFluentQuery(_graphClient) as ICypherFluentQuery;
        q = q.Match(string.Format(matchStringTemplate, id));

        q = q.OptionalMatch("(post:Post)-[mentionedUsersRelation:HAS_MentionedUsers]->(allAssignees:User)");
        q = q.OptionalMatch("(post:Post)-[authorRelation:HAS_Author]->(author:User)");
        q = q.OptionalMatch("(post:Post)-[hashtagRElation:HAS_HashTags]->(hashtags:HashTag)");
        q = q.OptionalMatch("(post:Post)-[HasAttachmentRelation:HAS_Attachments]->(attachment:PostAttachment)");

        q = q.OptionalMatch("(parents:Post)-[pmentionedUsersRelation:HAS_MentionedUsers]->(pallAssignees:User)");
        q = q.OptionalMatch("(parents:Post)-[pauthorRelation:HAS_Author]->(pauthor:User)");
        q = q.OptionalMatch("(parents:Post)-[phashtagRElation:HAS_HashTags]->(phashtags:HashTag)");
        q = q.OptionalMatch("(parents:Post)-[pHasAttachmentRelation:HAS_Attachments]->(pattachment:PostAttachment)");

        var rq = q.Return((post, parents,  allAssignees, author, hashtags, attachment,

            pallAssignees, pauthor, phashtags, pattachment) => new
        {
            Post = post.As<Post>(),
            Parent = parents.As<Post>(),
            Author = author.As<IdentityUser>(),
            MentionedUsers = allAssignees.CollectAsDistinct<IdentityUser>(),
            Attachments = attachment.CollectAsDistinct<PostAttachment>(),
            HashTags = hashtags.CollectAsDistinct<HashTag>()
        })
        .OrderByDescending("post.CreationDate");

        var result = rq.Results;
        var results = result.Select(p => new Post()
        {
            Id = p.Post.Id,

            Text = p.Post.Text,
            CreationDate = p.Post.CreationDate,
            Author = p.Author,
            MentionedUsers = p.MentionedUsers.Select(m => m.Data).ToArray(),
            HashTags = p.HashTags.Select(h => h.Data).ToArray(),
            Attachments = p.Attachments.Select(a => a.Data).ToArray()
        });
        return results.ToList();
    }

Cypher会是这样的：

 MATCH (post:Post {Id:9601})-[r:HAS_Parent*]->(parents:Post)

OPTIONAL MATCH (post:Post)-[mentionedUsersRelation:HAS_MentionedUsers]->(allAssignees:User)
OPTIONAL MATCH (post:Post)-[authorRelation:HAS_Author]->(author:User)
OPTIONAL MATCH (post:Post)-[hashtagRElation:HAS_HashTags]->(hashtags:HashTag)
OPTIONAL MATCH (post:Post)-[HasAttachmentRelation:HAS_Attachments]->(attachment:PostAttachment)
OPTIONAL MATCH (parents:Post)-[pmentionedUsersRelation:HAS_MentionedUsers]->(pallAssignees:User)

OPTIONAL MATCH (parents:Post)-[pauthorRelation:HAS_Author]->(pauthor:User)
OPTIONAL MATCH (parents:Post)-[phashtagRElation:HAS_HashTags]->(phashtags:HashTag)
OPTIONAL MATCH (parents:Post)-[pHasAttachmentRelation:HAS_Attachments]->(pattachment:PostAttachment)
RETURN post AS Post, collect(distinct parents) AS Parent, author AS Author, collect(distinct allAssignees) AS MentionedUsers, collect(distinct attachment) AS Attachments, collect(distinct hashtags) AS HashTags
ORDER BY post.CreationDate DESC

但问题是我不知道如何将结果加载到节点的层次结构strutuer及其后C＃类中的父节点。

当我在db上测试查询时，cypher结果是我正在寻找的。但是一切都搞砸了C＃对象。

这是neo4jDB中的查询结果：

Post Parents

Answer 1

如果您的Post类有多个父母帖子，那么我认为您应该更改

public Post Parent { get; set; }

类似

public IEnumerable<Post> Parent { get; set; }

然后，您可以将cypher结果中的所有父节点映射到此属性

使用Neo4jClient从Neo4j获取分层数据到C＃对象结构

1 个答案: