【问题标题】:Time based data query with Neo4J showing more relations than expected使用 Neo4J 的基于时间的数据查询显示比预期更多的关系
【发布时间】:2016-06-11 09:59:57
【问题描述】:

我正在努力思考 Neo4J 和基于时间的数据。

所以我基本上想要构建的是一个数据结构,它能够在某个时间给我一个跟踪节点(页面视图)及其引荐来源网址和引荐来源网址。

我的问题是,如果我将数据及其与时间树的关系保存起来,仍然会出现在按小时查询某个时间时不应该看到的关系。

在研究过程中,我发现了这篇关于 modeling time series data with neo4j 的文章。

到目前为止一切进展顺利,但引用者及其子关系并未被时间抽象。

为了更好地说明问题,这里首先介绍数据结构:

我创建了一个索引:

CREATE INDEX ON :Year(value);
CREATE INDEX ON :Month(value);
CREATE INDEX ON :Day(value);
CREATE INDEX ON :Hour(value);
CREATE INDEX ON :Minute(value);
CREATE INDEX ON :Second(value);

然后把时间节点放在那里:

//Create Time Tree with Day Depth
WITH range(2015, 2017) AS years, range(1,12) AS months
FOREACH(year IN years |
   CREATE (y:Year {value: year})
   FOREACH(month IN months |
     CREATE (m:Month {value: month})
    MERGE (y)-[:CONTAINS]->(m)
    FOREACH(day IN (CASE
                       WHEN month IN [1,3,5,7,8,10,12] THEN range(1,31)
                      WHEN month = 2 THEN
                        CASE
                          WHEN year % 4 <> 0 THEN range(1,28)
                           WHEN year % 100 = 0 AND year % 400 = 0 THEN range(1,29)
                           ELSE range(1,28)
                         END
                       ELSE range(1,30)
                     END) |
       CREATE (d:Day {value: day})
       MERGE (m)-[:CONTAINS]->(d))))

如果我现在保存数据:

MERGE (a:tracking {ip:'someniceid', type:'page_view', timestamp:'2154645'})
MERGE (f:Domain {name:'domain1.com'})
MERGE (e:Domain {name:'domain2.com'})
MERGE (d:Domain {name:'domain3.com'})
MERGE (z:Domain {name:'domain4.com'})
MERGE (a)-[:CAME_FROM]->(f)
MERGE (f)-[:REFERRED_BY]->(e)
MERGE (e)-[:REFERRED_BY]->(d)
MERGE (d)-[:REFERRED_BY]->(z)
WITH a, 2016 AS y 
MATCH (year:Year {value: y})
WITH a, year, 5 AS m 
MATCH (year)-[:CONTAINS]->(month:Month {value: m})
WITH a, month, 9 AS d 
MATCH (month)-[:CONTAINS]->(day:Day {value: d})
WITH a, day, 14 AS h 
MERGE (day)-[:CONTAINS]->(hour:Hour {value: h})
MERGE (a)-[:HAPPENED_ON]->(hour)

我得到以下带有查询的图表:

MATCH (y)-[:CONTAINS]->(m:Month {value: 5}) WITH y, m
MATCH (m)-[:CONTAINS]->(d {value: 9}) WITH y, m, d
MATCH (d)-[:CONTAINS]->(h {value: 14}) WITH y, m, d, h
MATCH (a:tracking)-[:HAPPENED_ON]->(h),(a)-[:CAME_FROM|:REFERRED_BY*]->(dom) RETURN dom AS D, a AS A

当我现在再保存一个数据集时,唯一的区别是更改小时和域(而不是我们现在有域 6 的域 4),例如:

MERGE (a:tracking {ip:'someniceid', type:'page_view', timestamp:'2154645'})"
MERGE (f:Domain {name:'domain1.com'})
MERGE (e:Domain {name:'domain2.com'})
MERGE (d:Domain {name:'domain3.com'})
MERGE (z:Domain {name:'domain6.com'})
MERGE (a)-[:CAME_FROM]->(f)
MERGE (f)-[:REFERRED_BY]->(e)
MERGE (e)-[:REFERRED_BY]->(d)
MERGE (d)-[:REFERRED_BY]->(z)
WITH a, 2016 AS y 
MATCH (year:Year {value: y})
WITH a, year, 5 AS m 
MATCH (year)-[:CONTAINS]->(month:Month {value: m})
WITH a, month, 9 AS d 
MATCH (month)-[:CONTAINS]->(day:Day {value: d})
WITH a, day, 10 AS h 
MERGE (day)-[:CONTAINS]->(hour:Hour {value: h})
MERGE (a)-[:HAPPENED_ON]->(hour)

因此,对于上面的相同查询,又添加了一个引荐来源网址,我认为这应该发生,因为与跟踪节点相关的时间(小时)节点不同:

尽管跟踪连接到不同的小时节点,但仍显示引荐关系!我做错什么了?对我来说,域 6 不应该是可见的,因为相关的跟踪没有与那个时间节点连接......有人有想法吗?

【问题讨论】:

    标签: neo4j cypher graph-databases


    【解决方案1】:

    问题是对于每个被监控的事件merge 没有为域创建新记录,并且您存储了错误的域序列。尝试为每个跟踪创建指向域的链接:

    MERGE (a:tracking {ip:'someniceid', type:'page_view', timestamp:'2154645'})
    MERGE (_f:Domain {name:'domain1.com'})
    MERGE (_e:Domain {name:'domain2.com'})
    MERGE (_d:Domain {name:'domain3.com'})
    MERGE (_z:Domain {name:'domain4.com'})
    CREATE (f:Symlink)-[:Symlink]->(_f)
    CREATE (e:Symlink)-[:Symlink]->(_e)
    CREATE (d:Symlink)-[:Symlink]->(_d)
    CREATE (z:Symlink)-[:Symlink]->(_z)
    MERGE (a)-[:CAME_FROM]->(f)
    MERGE (f)-[:REFERRED_BY]->(e)
    MERGE (e)-[:REFERRED_BY]->(d)
    MERGE (d)-[:REFERRED_BY]->(z)
    WITH a, 2016 AS y 
    MATCH (year:Year {value: y})
    WITH a, year, 5 AS m 
    MATCH (year)-[:CONTAINS]->(month:Month {value: m})
    WITH a, month, 9 AS d 
    MATCH (month)-[:CONTAINS]->(day:Day {value: d})
    WITH a, day, 14 AS h 
    MERGE (day)-[:CONTAINS]->(hour:Hour {value: h})
    MERGE (a)-[:HAPPENED_ON]->(hour)
    

    【讨论】:

    • 感谢您的回答。我有一个问题:在您看来,将域与时间节点相关联是否也有意义?
    • @Jurudocs 对不起,我不明白你的问题。你能解释一下吗?
    • 可以说我想获得 domain4.com 的跟踪总数,将每个域与一个小时相关联是否有意义,例如:(domain)-[:VISITED_ON]->(hour) ?
    • @Jurudocs 我认为是这样的:MATCH p = (hour:Hour)&lt;-[:HAPPENED_ON]-(a:tracking)-[:CAME_FROM|:REFERRED_BY*]-&gt;(s:Symlink)-&gt;(_z:Domain {name:'domain4.com'}) RETURN count(p)
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