给定一组强连接图的节点作为输入，我们可以获得它们之间的子图和路径遍历

Question

I have this requirement in ArangoDB AQL: I have a graph created with Document collection for node and Edge collection for directed edge relation.

I want to input a subset of list of nodes as input to AQL query and get all the node traversals /sub graph as the output.

How to achieve this from AQL? I want to know the relation between given nodes in that way. Please comment if more details are needed.

I know below query now

FOR v IN 1..1 INBOUND[or OUTBOUND] 'Collection/_key' EdgeCollection
OPTIONS {bfs: true}
RETURN v

Answer 1

I'd recommend reviewing the queries on the ArangoDB sample page where it shows how it performs graph queries, and how to review the results.

In your sample query above you are only returning v (vertex information) as in FOR v IN .

That returns only the last vertex from every path that the query returns, it doesn't return edge or path information.

For that you need to test with FOR v, e, p IN and it will return extra information about the last edge (e), and the path (p) it took.

In particular look at the results of p as it contains a JSON object that holds path information, which is a collection of vertices and edges.

By iterating through that data you should be able to extract the information you require.

AQL gives you many tools to aggregate, group, filter, de-duplicate, and reduce data sets, so make sure you look at the wider language functions and practice building more complex queries.