[S2GRAPH-234] Add a meta field(source_id, target_id) to GraphQL Edge Query (label)

• Type: Improvement
• Status: To Do
• Priority: Minor
• Resolution: Unresolved
• Component/s: s2graphql
• Assignee: Unassigned
• Reporter: Daewon Jeong
• Created: 01/Aug/18 05:45
• Updated: 01/Aug/18 05:45

Description

Add a meta field(source_id, target_id) to GraphQL Edge Query (label)

In Vertex Query(ServiceColumn) there is a fixed field called id.
However, there is only a ServiceColumn for the connected source/target in the Edge (label).

Therefore, in order to access the Source/Target ServiceColumn id of an Edge at the time of GraphQL query,
it is necessary to access in the same format as the corresponding ServiceColumn

{ id }

This is logically very clear, but it is inconvenient in actual use.

For more convenient queries, add a meta field to the Edge such as _source, _target, and so on.

The `source_id` indicates the id value of the Source ServiceColumn.
The `target_id` indicates the id value of the Target ServiceColumn.

If the above applies, you can query all of them in the following two ways.

 as is

{
  s2graph {
    User(id: "daewon") {
      id
      Like(limit: 10) {
        Book {
          id
        }
      }
    }
  }
}

to be

{
  s2graph {
    User(id: "daewon") {
      id
      Like(limit: 10) {      
        target_id
      }
    }
  }
}