Batch insert nodes and relations neo4jclient

问题

I have many nodes and edges in a list. Currently I'm looping through the list and inserting each node with a query which is very slow. How do I perform a batch insert using neo4jclient?

Node object:

public class myNode
{
    public int id { get; set; }
    public int floor { get; set; }
    public double x { get; set; }
    public double y { get; set; }
}

Current method for inserting a node:

public static void addNode(GraphClient client, myNode node, string nodeName)
{
    client.Cypher
       .Create("(" + nodeName + ":Node {node})")
       .WithParams(new { node })
       .ExecuteWithoutResults();
}

Current method for inserting List of nodes:

List<myNode> nodeList;
foreach(var elem in nodeList)
    addNode(client, elem, "foo");

回答1:

Instead of just passing a single node into your Cypher, you could pass in the collection. According to the Neo4j manual

By providing Cypher an array of maps, it will create a node for each map

See the section Create multiple nodes with a parameter for their properties in the Neo4j Manual v2.2.2.

Therefore your C# code will become simplified and should perform better.

public static void AddNodes(GraphClient client, List<MyNode> nodes)
{
    client.Cypher
       .Create("(n:Node {nodes})")
       .WithParams(new { nodes })
       .ExecuteWithoutResults();
}

Hope that helps.

回答2:

For completeness the following is an example that can be adapted to bulk load relationships and their properties using neo4jclient.

public void CreateRelationships(List<RelationshipCommon> relationships)
{
            graphClient.Cypher
            .Unwind(relationships, "relationship")
            .Match("(grant:GRANT)", "(target:THEME)")
            .Where("grant.node_id = relationship.SourceEntityId and target.node_id = relationship.TargetEntityId")
            .Create("grant-[r:IS_IN_THEME]->target")
            .Set("r.relationship_id = relationship.RelationshipId")
            .Set("r.grant_proportional_value = relationship.ProportionalValue")
            .ExecuteWithoutResults();
}

The relationships are a List collection of type RelationshipCommon. RelationshipCommon has the following structure

    public class RelationshipCommon
{
    public string SourceEntityId { get; set; }
    public string TargetEntityId { get; set; }
    public string RelationshipId { get; set; }
    public long ProportionalValue { get; set; }
}

On my development VM this code loaded 54000 relationships in 6s.

来源：https://stackoverflow.com/questions/30868905/batch-insert-nodes-and-relations-neo4jclient

标签

cypher

neo4jclient