Question

我有一个包含10行的小样本数据集，我从csv文件导入，其中包含名为TEvent的节点

LOAD CSV WITH HEADERS FROM "file:///path/to/file.csv" AS rec
CREATE (te: TEvent {l: rec.L, c: rec.C, t: rec.T, x: rec.X, us: rec.US, v: rec.V, d: rec.D, u: rec.U, h: rec.H, lc: rec.L+"_"+rec.C, lch: rec.L+"_"+rec.C+"_"+rec.H})

示例文件内容为

L,C,T,H,V,D,U,X,US

158,26823,2,2,.03,4.33,1.06,3,1

854,26843,2,2,.13,14.04,3.21,5,1.79

130,26861,2,2,.05,3.39,2.52,3,2.48

818,26863,2,2,.13,2.15,1.42,5,1.27

835,26880,2,2,.01,3.74,1.94,4,2.35

873,26902,2,2,20.27,24.65,8.69,12,4.74

187,26903,2,2,.15,.79,.5,4,.56

167,26941,2,2,0,0,0,0,0

147,26942,2,2,.36,.12,.27,2,.22

130,26982,2,2,.17,7.49,7.06,3,6.48

我使用以下Cypher语句创建了时间轴索引

  WITH range(2014, 2020) AS years, range(1,12) as months, range(0,23) as hours
  FOREACH(year IN years |
    MERGE (y:Year {year: year})
    FOREACH(month IN months |
      CREATE (m:Month {month: month})
      MERGE (y)-[:HAS_MONTH]->(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 THEN range(1,29)
                            WHEN year % 400 <> 0 THEN range(1,29)
                            ELSE range(1,28)
                          END
                        ELSE range(1,30)
                      END) |     
        CREATE (d:Day {day: day})
        MERGE (m)-[:HAS_DAY]->(d)
        FOREACH(hour IN hours |
              CREATE (h:Hour {hour: hour})
              MERGE (d)-[:HAS_HOUR]->(h)))))

现在，我尝试使用

将创建的TEvent节点中的属性H与时间线中的小时相关联

MATCH (te: TEvent)

MATCH (y: Year {year: 2016})-[]->(m: Month {month: 7})-[]->(d: Day {day: 4})-   []->(h:Hour {hour: te.h})

MERGE (h)<-[:AT]-(te)

RETURN h;

一致地返回（没有变化，没有记录）。

然后，我使用

创建了3个节点

        CREATE (:A {h: 2}), (:A {h:3}), (:A{h:6})

现在，如果我尝试仅更改标签的相同尝试

MATCH (te: A)

MATCH (y: Year {year: 2016})-[]->(m: Month {month: 7})-[]->(d: Day {day: 4})-[]->(h:Hour) WHERE h.hour = te.h

MERGE (h)<-[:AT]-(te)

RETURN h;

返回预期结果

h

"{""month"":7,""hour"":2,""year"":2016,""day"":4}"

"{""month"":7,""hour"":3,""year"":2016,""day"":4}"

"{""month"":7,""hour"":6,""year"":2016,""day"":4}"

我无法理解为什么第一个失败以及如何纠正它。

感谢任何帮助。 TIA。

干杯，维文

Answer 1

默认情况下，CSV的单元格都是字符串。

您需要对数字数据使用toInt(row.h)，并在图表中使用数字。

Neo4j匹配和合并 - 使用LOAD CSV

1 个答案: