如何通过输入边缘的数量进行计数和排序
我试图让那些出演过最多电影的十个人获得最终电影的名字和电影数量。 我正在使用IMDB数据集。
这是我到目前为止：
arangosh [_system]> var Graph = require("org/arangodb/graph").Graph;
arangosh [_system]> var db = require("org/arangodb").db;
arangosh [_system]> statement = db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(EDGES(imdb_edges, vert, "outbound", [{type: "ACTS_IN"}]))) RETURN {"name": vert.name, "count": edge_count}'})
[object ArangoStatement]
arangosh [_system]> cursor = statement.execute()
[object ArangoQueryCursor]
arangosh [_system]> cursor.next()
{
"name" : "Stephanie Faracy",
"count" : 0
}
我如何使用AQL来做到这一点？
没有索引：以下将返回前10名：
arangosh [_system]> db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(EDGES(imdb_edges, vert, "outbound", [{"type": "Role", "$label": "ACTS_IN"}]))) SORT edge_count DESC LIMIT 10 RETURN {"name": vert.name, "count": edge_count}'}).execute().toArray()
[
{
"name" : "Clint Eastwood",
"count" : 148
},
{
"name" : "Claude Jade",
"count" : 142
},
{
"name" : "Samuel L. Jackson",
"count" : 122
},
{
"name" : "Armin Mueller-Stahl",
"count" : 112
},
{
"name" : "Gérard Depardieu",
"count" : 104
},
{
"name" : "Marisa Mell",
"count" : 104
},
{
"name" : "Robert De Niro",
"count" : 104
},
{
"name" : "Bruce Willis",
"count" : 96
},
{
"name" : "Jackie Chan",
"count" : 94
},
{
"name" : "Michael Caine",
"count" : 90
}
]
基本上你也可以使用“排序”来为LET创建的变量。 限制允许您限制为TOP 10.请注意，顶点中的类型是'角色'，标签是'ACTS_IN'。
将数字添加到文档并使用排序后的索引会更有效。 但这需要更新文档。
arangosh [_system]> c = db._createStatement({query: 'FOR vert IN imdb_vertices FILTER vert.type == "Person" LET edge_count = (LENGTH(EDGES(imdb_edges, vert, "outbound", [{"type": "Role", "$label": "ACTS_IN"}]))) RETURN {"_key": vert._key, "count": edge_count}'}).execute()
[object ArangoQueryCursor]
arangosh [_system]> while (c.hasNext()) { var d = c.next(); db.imdb_vertices.update(d._key, {COUNT: d.count}); }
arangosh [_system]> db.imdb_vertices.ensureSkiplist("COUNT");
arangosh [_system]> x = db._createStatement({query: 'FOR vert in imdb_vertices FILTER vert.COUNT >= 0 SORT vert.COUNT DESC LIMIT 10 RETURN vert'}).execute()
[object ArangoQueryCursor]