Reputation: 3
I'm very new to neo4j. I've read this question (Cypher Query not finding Node) but it does not work. I'm getting the error, the the auto_node_index was not found. Perhaps it is because I'm using the BatchInserter?
For my experiment, I'm using neo4j 1.8.2 and the programming language Java with the embedded database.
I want to put some data to the database using the BatchInserter and the BatchInserterIndex like explained on http://docs.neo4j.org/chunked/milestone/batchinsert.html.
BatchInserter myInserter = BatchInserters.inserter(DB_PATH);
BatchInserterIndexProvider indexProvider =
new LuceneBatchInserterIndexProvider( myInserter );
BatchInserterIndex persons =
indexProvider.nodeIndex( "persons", MapUtil.stringMap( "type", "exact" ) );
persons.setCacheCapacity( "name", 10000 );
First I read the data from a TGF-file, create the nodes and put it to the inserter like this:
properties = MapUtil.map("name", actualNodeName, "birthday", birthdayValue);
long node = myInserter.createNode(properties);
nodes.add(node);
persons.flush();
The insert works fine, but when I want to search a node with Cypher, the result is empty
ExecutionEngine engine = new ExecutionEngine( db );
String query =
"start n=node:persons(name='nameToSearch') "
+ " match n-[:KNOWS]->m "
+ " return n.id, m ";
ExecutionResult result = engine.execute( query );
System.out.println(result);
On the other side, when I'm using the Traverser-class and start the search on the rootnode, I receive the nodes wich are connetced by the node with the name "nameToSearch".
Can anybody explain me, why I can't get the nodes with Cypher!
here is the complete method for the batch insert:
public long batchImport() throws IOException{
String actualLine;
ArrayList<Long> nodes = new ArrayList<Long>();
Map<String,Object> properties = new HashMap<String,Object>();
//delete all nodes and edges in the database
FileUtils.deleteRecursively(new File(DB_PATH ));
BatchInserter myInserter = BatchInserters.inserter(DB_PATH);
BatchInserterIndexProvider indexProvider =
new LuceneBatchInserterIndexProvider( myInserter );
BatchInserterIndex persons =
indexProvider.nodeIndex( "persons", MapUtil.stringMap( "type", "exact" ) );
persons.setCacheCapacity( "name", 10000 );
long execTime = 0;
try{
//Get the file which contains the graph informations
FileReader inputFile = new FileReader(UtilFunctions.searchFile(new File(PATH_OUTPUT_MERGED_FILES), "nodesAndEdges").get(0));
LineNumberReader inputLine = new LineNumberReader(inputFile);
// Read nodes up to symbol #
execTime = System.nanoTime();
while ((actualLine=inputLine.readLine()).charAt(0) != '#'){
StringTokenizer myTokenizer = new StringTokenizer(actualLine);
// Read node number
String actualNodeNumber = myTokenizer.nextToken();
// Read node name
String actualNodeName = myTokenizer.nextToken() + " " + myTokenizer.nextToken();
//Read property
myTokenizer.nextToken();
String actualNodePropertyKey = BIRTHDAY_KEY;
String actualNodePropertyValue = myTokenizer.nextToken();
actualNodePropertyValue = actualNodePropertyValue.substring(1, actualNodePropertyValue.length()-1);
// Insert node information
properties = MapUtil.map("name", actualNodeName, "birthday", actualNodePropertyValue, "id", actualNodeNumber);
long node = myInserter.createNode(properties);
nodes.add(node);
persons.flush();
}
// Read edges up to end of file
int countEdges = 0;
while ((actualLine=inputLine.readLine()) != null){
StringTokenizer myTokenizer = new StringTokenizer(actualLine);
// Read start node number
String actualStartNodeNumber = myTokenizer.nextToken();
// Read destination node number
String actualDestinationNodeNumber = myTokenizer.nextToken();
// Read relationship type
String actualRelType = myTokenizer.nextToken();
// Insert node information into ArrayList
int positionStartNode = Integer.parseInt(actualStartNodeNumber);
int positionDestinationNode = Integer.parseInt(actualDestinationNodeNumber);
properties.clear();
if (countEdges == 0) {
myInserter.createRelationship(0, nodes.get(positionStartNode-1), RelType.ROOT, properties);
myInserter.createRelationship(nodes.get(positionStartNode-1), nodes.get(positionDestinationNode-1), RelType.KNOWS, properties);
}
else
{
myInserter.(nodes.get(positionStartNode-1), nodes.get(positionDestinationNode-1), RelType.KNOWS, properties);
}
countEdges++;
}
indexProvider.shutdown();
myInserter.shutdown();
execTime = System.nanoTime() - execTime;
// Close input file
inputLine.close();
inputFile.close();
}
catch (Throwable e){
System.out.println(e.getMessage());
e.printStackTrace();
}
return execTime;
}
Upvotes: 0
Views: 230
Reputation: 39925
Your lacks a call to profiles.add(node, <indexProperties>)
. Therefore you're never adding anything to the index.
Upvotes: 0
Reputation: 39925
It is crucial that the code using Batchinserter API calls shutdown()
on both the BatchInserterIndexProvider
and BatchInserter
. Maybe you've missed this in your code.
If this does not solve the problem, please post your code.
Upvotes: 0