CODEWITHSUNDEEP
javaneo4jcypher
siliconchris
siliconchris

Reputation: 633

java neo4j cypher query to match node

I'm pretty sure I should see the error I'm making myself. And I'm also sure, I should know how to construct a decent cypher query within java, but I simply can't. It's late and I've been banging my head on this since the last 4 hours. So, I'm giving up.

I have a relatively simply cypher query I want to execute against an open transaction endpoint 

 http://localhost:7474/db/data/transaction/[# number]

So I figured, I do it just the way I do it when creating a node, but simply match instead of create:

  {"statements": [ {"statement": "MATCH (p:POST {properties}) RETURN p", "parameters": {"properties":{"sn_id": "TW", "id": "536627264453353472"}} } ] }

But the server tells me, I cannot use parameter maps in a match like that:

  TRACE Neo4JPersistence - sending cypher {"statements": [ {"statement": "MATCH (p:POST {properties}) RETURN p", "parameters": {"properties":{"sn_id": "TW", "id": "536627264453353472"}} } ] } to endpoint http://localhost:7474/db/data/transaction/75
  TRACE Neo4JPersistence - GET to http://localhost:7474/db/data/transaction/75 returned status code 200, returned data: {"commit":"http://localhost:7474/db/data/transaction/75/commit","results":[],"transaction":{"expires":"Sun, 23 Nov 2014 21:09:05 +0000"},"errors":[{"code":"Neo.ClientError.Statement.InvalidSyntax","message":"Parameter maps cannot be used in MATCH patterns (use a literal map instead, eg. \"{id: {param}.id}\") (line 1, column 15)\n\"MATCH (p:POST {properties}) RETURN p\"\n               ^"}]}
  ERROR Neo4JPersistence - ERROR :: [{"message":"Parameter maps cannot be used in MATCH patterns (use a literal map instead, eg. \"{id: {param}.id}\") (line 1, column 15)\n\"MATCH (p:POST {properties}) RETURN p\"\n               ^","code":"Neo.ClientError.Statement.InvalidSyntax"}] - could not execute cypher statement at location http://localhost:7474/db/data/transaction/75

So, ok, I thought. Let's go for something simpler, and I constructed my cypher like this:

 {"statements": [ {"statement": "MATCH (p:SOCIALNETWORK {"sn_id": "TW"} ) RETURN p"} ] }

But for this, the server returns that it can not deserialize the request and that it does not like the s - whichever s that is.

Here's the stack trace for it:

 TRACE Neo4JPersistence - sending cypher {"statements": [ {"statement": "MATCH (p:SOCIALNETWORK {"sn_id": "TW"} ) RETURN p"} ] } to endpoint http://localhost:7474/db/data/transaction/76
 TRACE Neo4JPersistence - GET to http://localhost:7474/db/data/transaction/76 returned status code 200, returned data: {"commit":"http://localhost:7474/db/data/transaction/76/commit","results":[],"transaction":{"expires":"Sun, 23 Nov 2014 21:18:01 +0000"},"errors":[{"code":"Neo.ClientError.Request.InvalidFormat","message":"Unable to deserialize request: Unexpected character ('s' (code 115)): was expecting comma to separate OBJECT entries\n at [Source: org.eclipse.jetty.server.HttpConnection$Input@43b86dc2{HttpChannelOverHttp@12dfe4a{r=10,a=DISPATCHED,uri=/db/data/transaction/76},HttpConnection@7291ace0{FILLING},g=HttpGenerator{s=START},p=HttpParser{s=END,87 of 87}}; line: 1, column: 59]"}]}
 ERROR Neo4JPersistence - ERROR :: [{"message":"Unable to deserialize request: Unexpected character ('s' (code 115)): was expecting comma to separate OBJECT entries\n at [Source: org.eclipse.jetty.server.HttpConnection$Input@43b86dc2{HttpChannelOverHttp@12dfe4a{r=10,a=DISPATCHED,uri=\/db\/data\/transaction\/76},HttpConnection@7291ace0{FILLING},g=HttpGenerator{s=START},p=HttpParser{s=END,87 of 87}}; line: 1, column: 59]","code":"Neo.ClientError.Request.InvalidFormat"}] - could not execute cypher statement at location http://localhost:7474/db/data/transaction/76

I'm stuck and frustrated by now. Can anyone help me again???

Thanks so much in advance,

Christian

Upvotes: 2

Views: 3064

Answers (2)

yair
yair

Reputation: 9255

Since version 2.0.5, you CAN use a property map with MATCH¥ (and MERGE):

{
  "statements" : 
    [
      {
        "statement": "MATCH (p:SOCIALNETWORK {sn_id: {properties}.sn_id)} ) RETURN p",
        "parameters": { "properties": {"snid": "TW"} }
        }
    ]
}

Not quite yet as smooth as with CREATE but still an improvement.

¥ Unfortunately it's officially documented only for MERGE and not for MATCH, but tested and used everyday by yours truly

Upvotes: 0

Luanne
Luanne

Reputation: 19373

Unlike CREATE, MATCH cannot use a property map- it requires you to use literals. So your query should end up looking like this:

{
  "statements" : 
    [
      {
        "statement": "MATCH (p:SOCIALNETWORK {sn_id: {snid}} ) RETURN p",
        "parameters": {"snid": "TW"}
        }
    ]
}

In your second query, don't put the property key in quotes:

{"statements": 
 [
  {
    "statement": "MATCH (p:SOCIALNETWORK {sn_id: 'TW'} ) RETURN p"
  } 
 ] 
}

Upvotes: 4

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