graph - 类型错误 : Object # has no method 'indexOf'

Question

我正在尝试对来自 this answer 的查询进行变体.我希望对顶点做一些进一步的过滤，以便我可以自定义前十名(使其成为给定年份或类似角色最多的前十名 Actor )。

如果我尝试使用 NEIGHBORS 函数，我会收到以下错误:

arangosh [_system]> db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(NEIGHBORS(imdb_vertices, imdb_edges, vert, "outbound", [{"type": "Role", "$label": "ACTS_IN"}]))) SORT edge_count DESC LIMIT 10 RETURN {"name": vert.name,  "count": edge_count}'}).execute().toArray()
JavaScript exception in file '/usr/share/arangodb/js/client/modules/org/arangodb/arangosh.js' at 101,13: TypeError: TypeError: Object #<ShapedJson> has no method 'indexOf'
!      throw new TypeError(requestResult.errorMessage);
!            ^
stacktrace: TypeError: TypeError: Object #<ShapedJson> has no method 'indexOf'
    at Object.exports.checkRequestResult (/usr/share/arangodb/js/client/modules/org/arangodb/arangosh.js:101:13)
    at ArangoStatement.execute (/usr/share/arangodb/js/client/modules/org/arangodb/arango-statement.js:171:12)
    at (shell):1:290

由于 NEIGHBORS 似乎同时返回边和顶点(与返回边的 EDGES 不同)，我认为问题可能是这样，所以我尝试使用 path: false 选项使用 TRAVERSAL。
不幸的是，它给出了同样的错误:

db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(TRAVERSAL(imdb_vertices,imdb_edges, vert, "outbound", {paths: false, followEdges: [{"type": "Role", "$label": "ACTS_IN"}]}))) SORT edge_count DESC LIMIT 10 RETURN {"name": vert.name,  "count": edge_count}'}).execute().toArray()
JavaScript exception in file '/usr/share/arangodb/js/client/modules/org/arangodb/arangosh.js' at 101,13: TypeError: TypeError: Object #<ShapedJson> has no method 'indexOf'
!      throw new TypeError(requestResult.errorMessage);
!            ^
stacktrace: TypeError: TypeError: Object #<ShapedJson> has no method 'indexOf'
    at Object.exports.checkRequestResult (/usr/share/arangodb/js/client/modules/org/arangodb/arangosh.js:101:13)
    at ArangoStatement.execute (/usr/share/arangodb/js/client/modules/org/arangodb/arango-statement.js:171:12)
    at (shell):1:318

有人可以解释为什么我会收到此错误吗？

Answer 1

我认为问题在于上面查询中的 vert 是一个顶点对象，但预计它是一个顶点 _id(或顶点 _key)。这就是发生异常的原因。

第一个查询可以修改如下:

db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(NEIGHBORS(imdb_vertices, imdb_edges, vert._id, "outbound", [{"type": "Role", "$label": "ACTS_IN"}]))) SORT edge_count DESC LIMIT 10 RETURN {"name": vert.name,  "count": edge_count}'}).execute().toArray()