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Are there Label properties - Is there a Neo4j schema for Labels?


Are there Label properties - Is there a Neo4j schema for Labels?

By : Mike Romain
Date : November 21 2020, 07:31 AM
Hope that helps There is no such mechanism built in Neo4j today (the current version of Neo4j at the time of writing is 2.1.6). What you are describing is some sort of schema (if you compare e.g. DDL for a RDBMS) and Neo4j is basically schema free. This type of structural integrity is quite often handled in the application layer for NoSQL databases.
The only schema operations that are available today for Neo4j are described here.
code :


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Do labels and properties have an id value in Neo4j?

Do labels and properties have an id value in Neo4j?


By : user2577910
Date : March 29 2020, 07:55 AM
it should still fix some issue All nodes and relationships have IDs and can be looked up by their IDs. You can do it like this:
code :
MATCH (n) WHERE id(n) = 5 RETURN n;
Neo4j query: How to build many labels into a label?

Neo4j query: How to build many labels into a label?


By : Eric Zhan
Date : March 29 2020, 07:55 AM
I wish this helpful for you My example gets my tweets and my friends's tweets: , Looks like you want to combine collections of tweets. How's this?
code :
MATCH (me:User{user_id: "346"})-[:POSTS]->(t:Tweet)
WITH me, COLLECT(t) as myTweets
MATCH (me)-[:FOLLOWS]->(following:User)-[:POSTS]->(t:Tweet)
WITH myTweets + COLLECT(t) as allTweets
UNWIND allTweets as tweets
RETURN tweets
SKIP 10 LIMIT 10
MATCH (me:User{user_id: "346"})-[:POSTS|:FOLLOWS*1..2]->(t:Tweet)
RETURN t
SKIP 10 LIMIT 10
MATCH (t:Tweet{tweet_id: '1'}) 
CALL apoc.date.parseDefault(t.created_at, 'ms') YIELD value
SET t.created_milliseconds = value
RETURN t
Why can't I delete all labels and properties in Neo4j?

Why can't I delete all labels and properties in Neo4j?


By : Mason
Date : March 29 2020, 07:55 AM
will be helpful for those in need If you have indexes present, the labels and properties used in the indexes will show in the browser. Try looking at :schema.
Also keep note that this is meta data, it isn't necessarily the most accurate reflection of what's actually in your database.
Neo4j Create new label based on other labels with certain properties

Neo4j Create new label based on other labels with certain properties


By : user3042584
Date : March 29 2020, 07:55 AM
seems to work fine I think this is one of those just because you can do it in one Cypher statement doesn't mean you should situations, and you will almost certainly find this easier to do in application code.
Regardless, it can be done using APOC and by introducing an instanceId unique property on your Trajectory nodes.
code :
LOAD CSV FROM 'file:///export.csv' AS line
CREATE (:Point{trajectoryId: line[0], at: datetime(line[1]), cameraSid: line[2], activity: line[3],x: line[4], atEpochMilli: line[5], y: line[6], control: line[7], classQual: line[8], classType: line[9], uniqueIdentifier: line[10]})
CALL apoc.periodic.iterate( 
'
MATCH (p: Point) 
WHERE NOT (:Trajectory)-[:CONTAINS]->(p)
RETURN p
ORDER BY p.at
',
'
OPTIONAL MATCH (t: Trajectory { trajectoryId: p.trajectoryId, cameraSid: p.cameraSid, classQual: p.classQual, classType: p.classType })-[:CONTAINS]-(trajPoint:Point)
WITH p, t, max(trajPoint.at) as maxAt, min(trajPoint.at) as minAt
WITH p, max(case when t is not null AND (
      (p.at <= datetime(maxAt) + duration({ hours: 1 })) 
      AND 
      (p.at >= datetime(minAt) - duration({ hours: 1 }))
  ) 
  THEN t.instanceId ELSE NULL END) as instanceId
MERGE (tActual: Trajectory { trajectoryId: p.trajectoryId, cameraSid: p.cameraSid, classQual: p.classQual, classType: p.classType, instanceId: COALESCE(instanceId, randomUUID()) })
ON CREATE SET tActual.date = date(datetime(p.at))
MERGE (tActual)-[:CONTAINS]->(p)
RETURN instanceId
',
{ parallel: false, batchSize: 1 })
OPTIONAL MATCH (t: Trajectory { trajectoryId: p.trajectoryId, cameraSid: p.cameraSid, classQual: p.classQual, classType: p.classType })-[:CONTAINS]-(trajPoint:Point)
WITH p, t, max(trajPoint.at) as maxAt, min(trajPoint.at) as minAt
WITH p, max(case when t is not null AND (
      (p.at <= datetime(maxAt) + duration({ hours: 1 })) 
      AND 
      (p.at >= datetime(minAt) - duration({ hours: 1 }))
  ) 
  THEN t.instanceId ELSE NULL END) as instanceId
MERGE (tActual: Trajectory { trajectoryId: p.trajectoryId, cameraSid: p.cameraSid, classQual: p.classQual, classType: p.classType, instanceId: COALESCE(instanceId, randomUUID()) })
ON CREATE SET tActual.date = date(datetime(p.at))
MERGE (tActual)-[:CONTAINS]->(p)
RETURN instanceId
{ parallel: false, batchSize: 1 })
Neo4j labels and properties, and their differences

Neo4j labels and properties, and their differences


By : M3NT0R
Date : March 29 2020, 07:55 AM
Does that help Say we have a Neo4j database with several 50,000 node subgraphs. Each subgraph has a root. I want to find all nodes in one subgraph. , Let's work this through, step by step.
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