OrientDB 从多个边中选择唯一的顶点

Question

我有 2 个顶点 User 和 Stamp。顶点由三个边 Have、WishToHave 和 Selling 关联。

我希望选择与用户有任何关系的独特邮票。为此，我正在运行以下命令：

select expand(out('Have', 'WishToHave', 'Selling')) from #12:0

这个命令的问题是它返回 'Stamp1' 几次，因为它有 Have 和 Selling 边缘。

如何选择与 User1 相关的所有唯一/不同的 Stamp？

为这个例子初始化测试数据：

create class User extends V
create class Stamp extends V

create class Have extends E
create class WishToHave extends E
create class Selling extends E

create vertex User set name = 'User1'
create vertex Stamp set name = 'Stamp1'
create vertex Stamp set name = 'Stamp2'
create vertex Stamp set name = 'Stamp3'


create edge Have from (select from User where name = 'User1') to (select from Stamp where name = 'Stamp1')
create edge WishToHave from (select from User where name = 'User1') to (select from Stamp where name = 'Stamp2')
create edge Selling from (select from User where name = 'User1') to (select from Stamp where name = 'Stamp1')
create edge Selling from (select from User where name = 'User1') to (select from Stamp where name = 'Stamp3')

Answer 1

我用你的结构试过你的情况：

要检索唯一顶点，您可以使用DISTINCT() 函数。我可以举两个例子：

查询 1：在目标查询中使用 EXPAND()

SELECT EXPAND(DISTINCT(@rid)) FROM (SELECT EXPAND(out('Have', 'WishToHave', 'Selling')) FROM #12:0)

输出：

查询 2：在目标查询中使用 UNWIND

SELECT EXPAND(DISTINCT(out)) FROM (SELECT out('Have', 'WishToHave', 'Selling') FROM #12:0 UNWIND out)

输出：

希望对你有帮助