Neo4j - SPLessons
SPLessons 5 Steps, 3 Clicks
5 Steps - 3 Clicks

Neo4j Traversal

Neo4j Traversal

shape Description

By using traversals one can traverse the graph. In essence, that means the user can retrieve a path, a piece of a complete graph. In a traversal the configurations should be followed deeply and should maintain a relationship that has be followed. A traversal always start at one node. In a state the results immediately, and can also perform it later. And by using a paged traversal a URL back is generated. It will pick one node as a starting point, using it's traversal URL. As an extension, it will request the API to return from the next path. And if the user want the whole path one need to specify path. This will return a start node and the end node with the rest of the paths or URL'S. If the user want all complete nodes and the relationships in the path, use full path and utilize the node if only interested in nodes and relationship if the user wants relationships.

shape Conceptual figure

The further details of the traversals are contained in a request JSON attachment. And can easily absorb the traversals are a bit more complicated than everything as it covered before. In the first line the user can check the traversal URL of the node extended with what we want from the path and can utilize the node extensions. In the attached JSON, we first find an order parameter. This specifies the order in which the nodes are visited. There are two options,breadth first or depth first. These are graph theory terms. In the breadth first all nodes connected to the start node are first visited, then all the nodes attached to the first node visited. In depth first the traversal goes as deep as it can first and then backtracks to find the other nodes. Return_filters is a java script expression that is executed for each position in the graph. If it returns true, the node or relationships is included in the result. Currently JavaScript is the only language supported. Beware of the security risks if the user dynamically build the java script from the user input. The prune_evaluate is also a java script expression. It is executed after a position is retrieved and it determines if the traversal should be continues. The traversals stops if the number of position visited is greater than 10.

Batch Operations

shape Description

Batch operations allows the user to do multiple operations in one request using a post request to the batch URL. The different operations are issued as an array with an HTTP method, a relative URL to post to and a request body. Which is normally attached to the request and while creating 2 nodes each operation ID will be refer in later operational executions with in the same batch. In the second column, a relationship is created on the node created first pointed to the node created second.

Summary

shape Key Points

  • Traversals - Is a graph traversal that refers to the process of visiting each node in a data structures.
  • Batch operations - Allows the client for performing operations.