Скачать или смотреть How to Perform Traversal in Gremlin Using Edge Label

Learn how to traverse a graph in Gremlin by using edge properties effectively. Discover step-by-step instructions to achieve your graph traversal goals.
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How to Perform Traversal in Gremlin Using Edge Label

Traversing a graph database with Gremlin can initially seem daunting, especially for beginners. One common task is to find nodes connected by edges with specific properties. In this post, we’ll explore how to find these nodes efficiently by performing a traversal in Gremlin focusing on edge labels.

Understanding the Problem

Imagine you have a graph with vertices representing buildings and edges representing paths between them. For example, consider the following set-up:

Vertices: A, B, C, D, E (all of type "building")

Edges: Multiple paths connecting these buildings, each with properties including an identifier.

You want to identify a path that only includes edges with the property ident set to ABC. The specific traversal you want is expressed as:

[[See Video to Reveal this Text or Code Snippet]]

To achieve this, we'll need to use a combination of Gremlin's traversal steps effectively.

Solution Breakdown

To find the path between nodes using a specific edge property, you'll use the following steps:

1. Starting Point

Begin your traversal at the vertex representing the starting building. In our case, it’s the building named "A". You need to filter only the edges having the specified property.

2. Using Repeat and Until Steps

We can utilize the repeat() step, which allows us to continuously traverse the graph until a condition is met. Here's how to structure your Gremlin query:

[[See Video to Reveal this Text or Code Snippet]]

g.V(): This initiates the traversal from all vertices in the graph.

has('building', 'name', 'A'): Filters to find the starting vertex with name "A".

repeat(outE('path').has('ident', 'ABC').inV()): This step will find outgoing edges labeled 'path' where the ident property is 'ABC' and move to the connected vertices.

until(outE('path').count().is(0)): This step ensures that the traversal stops where there are no more outgoing edges to follow.

path(): This function returns the complete path as a list of vertices, displaying the connection from 'A' to 'E'.

3. Execute and Analyze

Once you have entered this query into your Gremlin console or environment, execute it to see the results. You should get the complete path from vertex A through all subsequent vertices (B, C, D, and E) connected by the paths with the specified identifier.

Conclusion

Performing graph traversal in Gremlin can be simplified by understanding the syntax and methodology involved. By following the outlined steps, you can effectively navigate through your graph database, leveraging edge properties to find connected nodes efficiently.

Start experimenting with your own graphs, and don’t hesitate to tweak the queries to fit your specific data needs! Happy traversing!