使用 Neo4jClient 调用 TimeTree

Calling TimeTree using Neo4jClient

我正在使用下面的代码尝试从 Neo4jClient 调用 TimeTree。

其他简单的调用都可以,但这个调用什么也不做。没有错误,但也没有新的时间对象。

public class Trip
{
    public long Id { get; set; }
    public string Name { get; set; }
}

public class UUID
{
    public long Value { get; set; }
}

public class TimeStamp
{
    //public long Id { get; set; }
    //public string Name { get; set; }

    public long time { get; set; }
}


public class User
{
    public long Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
}

class Program
{
    static void Main(string[] args)
    {

        var client = new Neo4jClient.GraphClient(new Uri("http://localhost:7474/db/data"), "neo4j", "password");
        client.Connect();


        client.Cypher
            .Match("(n)")
            .DetachDelete("n")
            .ExecuteWithoutResults();


        var newUser = new User { Id = 456, Name = "Jim" };
        client.Cypher
            .Create("(user:User {newUser})")
            .WithParam("newUser", newUser)
            .ExecuteWithoutResults();

        var newTrip = new Trip { Id = 001, Name = "Antibes" };
        client.Cypher
            .Match("(traveller:User)")
            .Where((User traveller) => traveller.Id == 456)
            .Create("(traveller)-[:TRAVELLING]->(travelling:Trip {newTrip})")
            .WithParam("newTrip", newTrip)
            .ExecuteWithoutResults();

        var tstamp = client.Cypher
              .Match("(trip:Trip)")
              .Where((Trip trip) => trip.Name == "Antibes")
              .With("trip AS tripToLink")
              .Call("ga.timetree.events.attach({ node: 'tripToLink', time: 1483828451000, relationshipType: \"ARRIVING_ON\"})")
              .Yield("node")
              .Return(node => new { TimeStamp = node.As<TimeStamp>() });

以下内容在 Shell 中有效:

MATCH (trip:Trip)
WHERE trip.Name = "Antibes"
WITH trip
CALL ga.timetree.events.attach({node: trip, time: 1483828451000 , relationshipType: "ARRIVING_ON"})
YIELD node RETURN node

首先 - 将所有代码放在那里的工作做得很好,它让生活变得更轻松!

我认为这里的问题有两个方面:您拥有的 tstamp 变量的类型为:ICypherFluentQuery<???>(我使用“?”来表示您正在创建的匿名类型) - 所以你需要实际得到结果才能得到任何回应。在您调用 .Results 之前,您实际上并没有执行查询。

通常,我喜欢像您一样创建查询,然后在之后执行:

var tstamp = client.Cypher....
    /* rest of the query here */

var tStampResults = tstamp.Results;

执行此操作时,您可能会遇到错误:

BadInputException: java.lang.String cannot be cast to org.neo4j.graphdb.Node

如果您在控制台中查看您 运行 查询的响应 - 您会发现您实际上返回了:

╒═══════════════════════════╕
│"node"                     │
╞═══════════════════════════╡
│{"Id":"1","Name":"Antibes"}│
└───────────────────────────┘

那是因为你正在 YIELDing node,所以你只能转换为 Trip 类型:

var query = client.Cypher
    .Match("(trip:Trip)")
    .Where((Trip trip) => trip.Name == "Antibes")
    .With("trip")
    .Call("ga.timetree.events.attach({node: trip, time: 1483828451000 , relationshipType: \"ARRIVING_ON\"})")
    .Yield("node")
    .Return(node => node.As<Trip>()); //<-- Change here