获取arangodb中给定节点的连接节点列表

Question

我在 Arangodb 中构建了一个图表。

我正在努力满足以下要求。

给定一个节点，我需要一个连接到它的所有节点的列表以及它连接到的深度。

示例：

Customer2 -> 在深度 1 处连接到 Customer1， Customer3 -> 在深度 2 处连接到 Customer1，依此类推..

请帮助我实现这一目标。

Answer 1

假设你是using the pattern matching traversals，这很容易实现。

让我们尝试使用Knows Graph example 开始遍历Eve：

db._query(`FOR v, e IN 1..3 OUTBOUND 'persons/eve' 
           GRAPH 'knows_graph' 
           RETURN {v: v, e: e}`)
[ 
  { 
    "e" : { 
      "_from" : "persons/eve", 
      "_id" : "knows/156", 
      "_key" : "156", 
      "_rev" : "156", 
      "_to" : "persons/alice" 
    }, 
    "v" : { 
      "_id" : "persons/alice", 
      "_key" : "alice", 
      "_rev" : "130", 
      "name" : "Alice" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/alice", 
      "_id" : "knows/146", 
      "_key" : "146", 
      "_rev" : "146", 
      "_to" : "persons/bob" 
    }, 
    "v" : { 
      "_id" : "persons/bob", 
      "_key" : "bob", 
      "_rev" : "134", 
      "name" : "Bob" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/bob", 
      "_id" : "knows/150", 
      "_key" : "150", 
      "_rev" : "150", 
      "_to" : "persons/charlie" 
    }, 
    "v" : { 
      "_id" : "persons/charlie", 
      "_key" : "charlie", 
      "_rev" : "137", 
      "name" : "Charlie" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/bob", 
      "_id" : "knows/153", 
      "_key" : "153", 
      "_rev" : "153", 
      "_to" : "persons/dave" 
    }, 
    "v" : { 
      "_id" : "persons/dave", 
      "_key" : "dave", 
      "_rev" : "140", 
      "name" : "Dave" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/eve", 
      "_id" : "knows/159", 
      "_key" : "159", 
      "_rev" : "159", 
      "_to" : "persons/bob" 
    }, 
    "v" : { 
      "_id" : "persons/bob", 
      "_key" : "bob", 
      "_rev" : "134", 
      "name" : "Bob" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/bob", 
      "_id" : "knows/150", 
      "_key" : "150", 
      "_rev" : "150", 
      "_to" : "persons/charlie" 
    }, 
    "v" : { 
      "_id" : "persons/charlie", 
      "_key" : "charlie", 
      "_rev" : "137", 
      "name" : "Charlie" 
    } 
  }, 
  { 
    "e" : { 
      "_from" : "persons/bob", 
      "_id" : "knows/153", 
      "_key" : "153", 
      "_rev" : "153", 
      "_to" : "persons/dave" 
    }, 
    "v" : { 
      "_id" : "persons/dave", 
      "_key" : "dave", 
      "_rev" : "140", 
      "name" : "Dave" 
    } 
  } 
]

遍历中的每一步都将映射到列表中的一个对象。您还可以将 vertices（人）与 edges（知道）

的 _from 和 _to 属性联系起来

也可以只看路径；你可以使用路径属性：

db._query(`FOR v, e, p IN 2..2 OUTBOUND 'persons/eve' 
           GRAPH 'knows_graph' 
           RETURN {p: p}`)

我们只返回迭代结束点的路径，将其限制为 2 以便更好地查看；这是生成的路径之一：

[
  ...
  { 
    "p" : { 
      "edges" : [ 
        { 
          "_from" : "persons/eve", 
          "_id" : "knows/159", 
          "_key" : "159", 
          "_rev" : "159", 
          "_to" : "persons/bob" 
        }, 
        { 
          "_from" : "persons/bob", 
          "_id" : "knows/153", 
          "_key" : "153", 
          "_rev" : "153", 
          "_to" : "persons/dave" 
        } 
      ], 
      "vertices" : [ 
        { 
          "_id" : "persons/eve", 
          "_key" : "eve", 
          "_rev" : "143", 
          "name" : "Eve" 
        }, 
        { 
          "_id" : "persons/bob", 
          "_key" : "bob", 
          "_rev" : "134", 
          "name" : "Bob" 
        }, 
        { 
          "_id" : "persons/dave", 
          "_key" : "dave", 
          "_rev" : "140", 
          "name" : "Dave" 
        } 
      ] 
    } 
  } 
]