Hi,
the reason of using neo4j is the main problem of my question. Just as Toni
Menzel said "Directly falling back to the index service does not really
embrace why you are a graph db at all." The question is, because my employee
want to perform some project, within what he (me) will demonstrate the use
of graph db. That is the problem, because there is no any particular
problem, I am aiming to resolve, and for that and that I need graph db.
However, one thing which bothering me is : Can I perform selection like in
relational database (so I have saved some data some time ago, and I want to
retrieve it again)?
In all neo4j examples, data is retrieved from the same part of the code
which perform saving earlier.
Is it at all possible to select data, like 10 days after saving?
Every example is like this :
GraphDatabaseService graphDb = new
EmbeddedGraphDatabase("poc_test");
Transaction tx = graphDb.beginTx();
try {
for(CSVObject object : csv){
Node trigramme = graphDb.createNode();
Node cp = graphDb.createNode();
Node description = graphDb.createNode();
Node category = graphDb.createNode();
Relationship ispartOf = trigramme.createRelationshipTo(cp,
RelTypes.IS_PART_OF);
Relationship isDescribedBy =
trigramme.createRelationshipTo(description, RelTypes.IS_DESCRIBED_BY);
Relationship isCategorizedIn =
description.createRelationshipTo(category, RelTypes.IS_CATEGORIZED_IN);
trigramme.setProperty("value", object.getTrigram());
cp.setProperty("value", object.getCp());
description.setProperty("value", object.getDescription());
category.setProperty("value", object.getCategory());
ispartOf.setProperty("relationship", "ispartOf ");
isDescribedBy.setProperty("relationship", "ispartOf");
isCategorizedIn.setProperty("relationship", "ispartOf");
Traverser friendsTraverser = description.traverse(
Traverser.Order.BREADTH_FIRST,
StopEvaluator.DEPTH_ONE,
ReturnableEvaluator.ALL_BUT_START_NODE,
RelTypes.IS_DESCRIBED_BY,
Direction.INCOMING );
// Traverse the node space and print out the result
//System.out.println( "Testing values : " );
for ( Node friend : friendsTraverser )
{
System.out.println( "At depth : "+
friendsTraverser.currentPosition().depth()+" with
value : "+
friend.getProperty( "value" ) );
}
}
tx.success();
}catch (Exception e){
e.printStackTrace();
}
finally {
tx.finish();
graphDb.shutdown();
}
}
So Traverser is using the node previously created, in order to iterate over
database.
But, how can I perform (simple example), to save user's data when he
register, and after 10 days when he log in again, to retrieve that data? And
is this kind of concept, which I use in relational db, possible to apply to
graph database? I mean, if I cannot get saved data after some time, what is
the purpose of the graph db?
Hope you understood my problem and question, and thanks in advance to your
answers !
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