select expand(out().out()) get two same vertex?

[lightjiao]

I have a test graph below

a_1 ---[e_a_b]---> b_1
a_1 ---[e_a_b]---> b_2
b_1 ---[e_b_c]---> c_1
b_2 ---[e_b_c]---> c_1
execute sql

select expand(out("e_a_b").out("e_b_c")) from v_a

return two same vertex(two c_1), it's a BUG? or I used in a wrong way?
How can I get one single c_1 after select expand(out("e_a_b").out("e_b_c")) from v_aon my test data?
My purpose is to count friends of friends and sort by the result
How can I get this.
I know traverse out("e_a_b", "e_b_c") from (select from v_a where name = "a_1") ,but this only get one of the v_a(the a_1), I need a page of v_a and the count of relation's relation

My English is not very well, thanks reading.

data scripts

create class v_a extends v clusters 1;
create vertex v_a content {"name": "a_1"};
create class v_b extends v clusters 1;
create vertex v_b content {"name": "b_1"};
create vertex v_b content {"name": "b_2"};
create class v_c extends v clusters 1;
create vertex v_c content {"name": "c_1"};
create class e_a_b extends e clusters 1;
create edge e_a_b from (select from v_a) to (select from v_b);
create class e_b_c extends e clusters 1;
create edge e_b_c from (select from v_b) to (select from v_c);

OrientDB Version: 2.2.24

Java Version: 1.8.0_102

OS: centos 6.8

Expected behavior

select out().out() from v_areturn one vertex

Actual behavior

return two same vertex

[lightjiao]

select name, set(out("e_a_b").out("e_b_c")).size() from v_a

I… find the answer?

The problem is always solved after the problem is raised - -b

any better way?

the stackoverflow
https://stackoverflow.com/questions/45550381/orientdb-select-out-out-return-two-same-vertex/45550641#45550641

[luigidellaquila]

Hi @lightjiao

Yes, it's expected, you can also use .asSet(), but there is no particular advantage compared to your solution

Thanks

Luigi

[lightjiao]

@luigidellaquila Thank you ^_^