我使用cypher查询在neo4j中加载了一个数据集。当我加载数据时,我在单词之间发现了一些空值。 如何清理空值。 我的目标是找到字数统计频率。
我得到了结果results image在wordsenter code here
之间的一些空值
LOAD CSV FROM "file:///tmp1.csv" AS line
FIELDTERMINATOR ' '
FOREACH (w IN RANGE(0, SIZE(line)-2) |
MERGE (lx:Kbank{word:coalesce(line[w],'NOT SET')})
ON CREATE SET lx.count = 1
ON MATCH SET lx.count = lx.count + 1
MERGE (mx:Kbank{word:coalesce(line[w+1],'NOT SET')})
ON CREATE SET mx.count = 1
ON MATCH SET mx.count = mx.count + (case when w = SIZE(line)-2 then 1 else 0
end)
MERGE (lx)-[r:next]->(mx)
ON CREATE SET r.count = 1
ON MATCH SET r.count = r.count +1)
RETURN line
LIMIT 100
对于字数enter image description here我想删除NOT SET LIST
您可以在cypher中使用filter
函数来删除所有NULL
值:
LOAD CSV FROM "file:///tmp1.csv" AS line FIELDTERMINATOR ' '
WITH filter(x IN line WHERE x IS NOT NULL) AS line
...