[英]Creating conditional relationship while importing CSV into Neo4j
我有一个数据集,看起来像:
id s01 s02 s03 s04 s05 s06 s07 s08 s09 s10
U01 1 0 0 0 0 0 0 0 0 1
U02 1 0 0 0 0 0 0 0 0 0
U03 1 0 0 0 0 0 0 0 0 0
U04 0 1 0 0 0 0 0 0 0 0
U05 0 1 0 0 0 0 0 0 0 0
U06 0 0 1 0 0 0 0 0 1 0
U07 0 0 1 0 0 0 0 0 0 0
U08 0 0 1 0 0 0 0 0 0 0
U09 0 0 1 1 0 0 0 0 0 0
U10 0 0 0 1 0 0 0 0 0 0
U11 0 0 0 1 1 0 0 0 0 1
U12 0 0 0 0 1 0 0 0 0 0
U13 0 0 0 0 1 1 0 0 0 0
U14 0 0 0 0 0 1 1 0 0 0
U15 0 0 0 0 0 0 1 0 0 0
U16 0 0 0 0 0 0 1 1 0 0
U17 0 0 0 0 0 1 0 1 0 0
U18 0 0 0 0 0 0 0 1 0 0
U19 0 0 0 0 0 0 0 1 1 0
U20 0 1 0 0 0 0 0 0 1 0
我想将其导入Neo4j,节点为U01,U02,U03 ...和s01,s02,....,s10
节点已创建。 现在,我想基于值(0/1)创建关系:如果为1,则对应的节点之间应该存在关系。
就像第二行和第二列的值是1一样,这意味着我必须在U01
和S01
之间创建关系,而对于第二行第三列的值是0,所以我将跳过该值。
到目前为止,我正在尝试提出一个硬编码的解决方案:
LOAD CSV WITH HEADERS FROM file:///new.csv" AS line FIELDTERMINATOR '\t'
WITH line
MATCH (a:Users)
WHERE a.user_id = line.id
WITH line, a
RETURN CASE
WHEN TOINT(line.s01)=1 THEN CREATE (a)-[:watches]->(c:NewsMedia{ID:"s01"})
WHEN TOINT(line.s02)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s02"})
WHEN TOINT(line.s03)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s03"})
WHEN TOINT(line.s04)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s04"})
WHEN TOINT(line.s05)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s05"})
WHEN TOINT(line.s06)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s06"})
WHEN TOINT(line.s07)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s07"})
WHEN TOINT(line.s08)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s08"})
WHEN TOINT(line.s09)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s09"})
WHEN TOINT(line.s10)=1 THEN MERGE (a)-[:watches]->(b:NewsMedia{ID:"s10"})
END
错误出现在条件MERGE部分中, WHEN <condition> THEN MERGE ()-[]->()
,是否可以创建关系?
1)我认为您不能在CASE
使用MERGE
。
2)为了避免hardcored solution
您可以使用UNWIND
和KEYS
:
LOAD CSV WITH HEADERS FROM "file:///new.csv" AS line FIELDTERMINATOR '\t'
MERGE (a:Users {user_id: line.id})
WITH a, line
UNWIND KEYS(line) AS bid
WITH a, bid WHERE "id" <> bid AND TOINTEGER(line[bid]) = 1
MERGE (b:NewsMedia {ID: bid})
MERGE (a)-[r:watches]->(b)
RETURN a, r, b
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