如何使用变量动态创建 Neo4j/Cypher 标签？

Question

When I try:

CALL apoc.load.jdbc('jdbc:mysql://localhost/mysql?user=root&password=root&useUnicode=true&characterEncoding=utf8','select * from db')YIELD row
WHERE row.label = 'dis' MERGE (n:dis {name: row.keyword})
WHERE row.label = 'part' MERGE (n:part {name: row.keyword})

and there is an error

Neo.ClientError.Statement.SyntaxError: Invalid input 'H': expected 'i/I'

Answer 1

you can use the apoc fucntions to do this

CALL apoc.merge.node(['Label'], identProps:{key:value, …​}, onCreateProps:{key:value,…​}, onMatchProps:{key:value,…​}})

the following query will dynamically read label names and merge nodes with respective label

CALL apoc.load.jdbc('jdbc:mysql://localhost/mysql?user=root&password=root&useUnicode=true&characterEncoding=utf8','select * from db')YIELD row 
CALL apoc.merge.node([row.label], identProps:{name:row.keyword}, onCreateProps:{}, onMatchProps:{}}) YIELD node 
RETURN node 

Answer 2

If you intend to match node with specific label, you should probably use the MATCH (:label) clause instead of WHERE label = ...

CALL apoc.load.jdbc('jdbc:mysql://localhost/mysql?user=root&password=root&useUnicode=true&characterEncoding=utf8','select * from db')YIELD row
OPTIONAL MATCH (row:dis) MERGE (n:dis {name: row.keyword})
OPTIONAL MATCH (row:part) MERGE (n:part {name: row.keyword})