如何使用 gremlin 查询获取网络（2 级）人员撰写的最新 10 篇帖子？

Question

我有朋友，我的朋友也有朋友。我如何使用 gremlin 查询获取我网络（2 级）中的人撰写的最新 10 篇帖子？

Answer 1

鉴于你想获得用户u1的朋友和朋友的朋友的最后10条帖子：

u1.out('friend').copySplit(_().out('friend').except([u1]).out('post'), _().out('post')).exhaustMerge.dedup.order{it.b.ts <=> it.a.ts}[0..<10].map

给你：

==>{msg=f, ts=2015-03-08 12:09:11.567}
==>{msg=e, ts=2015-03-08 12:09:01.459}
==>{msg=d, ts=2015-03-08 12:08:56.339}
==>{msg=c, ts=2015-03-08 12:08:41.209}
==>{msg=b, ts=2015-03-08 12:08:21.086}

使用以下示例图：

import java.sql.Timestamp

g = new TinkerGraph()
u1 = g.addVertex('user1')
u2 = g.addVertex('user2')
u3 = g.addVertex('user3')
u4 = g.addVertex('user4')
u5 = g.addVertex('user5')

g.addEdge(u1,u2,'friend')
g.addEdge(u2,u1,'friend')
g.addEdge(u2,u3,'friend')
g.addEdge(u3,u2,'friend')
g.addEdge(u1,u3,'friend')
g.addEdge(u3,u1,'friend')
g.addEdge(u2,u4,'friend')
g.addEdge(u4,u2,'friend')
g.addEdge(u4,u5,'friend')
g.addEdge(u5,u4,'friend')

p1 = g.addVertex('post1',['ts': new Timestamp(System.currentTimeMillis() - 100000), 'msg':'a'])
p2 = g.addVertex('post2',['ts': new Timestamp(System.currentTimeMillis() - 80000), 'msg':'b'])
p3 = g.addVertex('post3',['ts': new Timestamp(System.currentTimeMillis() - 60000), 'msg':'c'])
p4 = g.addVertex('post4',['ts': new Timestamp(System.currentTimeMillis() - 45000), 'msg':'d'])
p5 = g.addVertex('post5',['ts': new Timestamp(System.currentTimeMillis() - 40000), 'msg':'e'])
p6 = g.addVertex('post6',['ts': new Timestamp(System.currentTimeMillis() - 30000), 'msg':'f'])
p7 = g.addVertex('post7',['ts': new Timestamp(System.currentTimeMillis() - 20000), 'msg':'g'])
p8 = g.addVertex('post8',['ts': new Timestamp(System.currentTimeMillis() - 10000), 'msg':'h'])
p9 = g.addVertex('post9',['ts': new Timestamp(System.currentTimeMillis()), 'msg':'i'])

g.addEdge(u1,p1,'post')
g.addEdge(u1,p9,'post')
g.addEdge(u2,p3,'post')
g.addEdge(u3,p6,'post')
g.addEdge(u4,p5,'post')
g.addEdge(u4,p2,'post')
g.addEdge(u4,p4,'post')
g.addEdge(u5,p7,'post')
g.addEdge(u5,p8,'post')

如何使用 gremlin 查询获取网络（2 级）人员撰写的最新 10 篇帖子？

How can I get the latest 10 posts those are written by people in my network (2 level) with gremlin query?

graph

orientdb

gremlin