CODEWITHSUNDEEP
pythonneo4jcypherpy2neo
Sun Park
Sun Park

Reputation: 13

What is correct Cypher Syntax?

I refer to Neo4j create nodes and relationships from pandas dataframe with py2neo and code with belows. But I got py2neo.database.status.CypherSyntaxError. Please verify below is right approach and let me know what is correct Cypher syntax.

My Code:

for line in reader:
    print(line['word'], line['similar_word'], line['probability'] )
    w1 = Node("Word", name = line['word'])
    w2 = Node("Word", name = line['similar_word'])
    graph.merge(w1|w2)
    graph.run('''
      MATCH (a:Paper),(b:Word)
      WHERE (a.name = 'Paper10' AND b.name = {$word1})
      CREATE (a)<-[o:ORIGINAL]-(b)
      ''', parameters = {'word1':line['word']})

py2neo.database.status.CypherSyntaxError:

Traceback (most recent call last):   File "test.py", line 24, in <module>
    ''', parameters = {'word1':line['word']})   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/database/__init__.py", line 731, in run
    return self.begin(autocommit=True).run(statement, parameters, **kwparameters)   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/database/__init__.py", line 1277, in run
    self.finish()   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/database/__init__.py", line 1296, in finish
    self._sync()   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/database/__init__.py", line 1286, in _sync
    connection.fetch()   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/packages/neo4j/v1/bolt.py", line 344, in fetch
    handler(*fields)   File "/root/miniconda3/lib/python3.6/site-packages/py2neo/database/__init__.py", line 961, in on_failure
    raise GraphError.hydrate(metadata) py2neo.database.status.CypherSyntaxError: Invalid input '$': expected whitespace, an identifier, UnsignedDecimalInteger, a property key name or '}' (line 3, column 53 (offset: 78)) "      WHERE (a.name = 'Paper10' AND b.name = {$word1})"

Upvotes: 1

Views: 256

Answers (1)

InverseFalcon
InverseFalcon

Reputation: 30397

For referencing a parameter, you can either use the $ syntax, or the {}, but not both. Try this with just $word1.

Upvotes: 1

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