OrientDB Find vertex is linked with a list of another vertex - orientdb

Question

i am discovering OrientDB and i have a problem :
I have two vertex definition :
Product
Criterion
And one Edge definition:
- IsRelatedToEdge
Thanks to IsRelatedToEdge, I can link one product to many criterion
In my example, i have populated the database with 5 products
shoe-1
shoe-2
shoe-3
hat-1
hat-2
and 4 criterions :
blue
red
hat
shoe
Then I linked products with criterion this way:
shoe-1 <=> shoe
shoe-1 <=> blue
shoe-2 <=> shoe
shoe-2 <=> red
shoe-3 <=> shoe
shoe-3 <=> blue
hat-1 <=> shoe
hat-1 <=> blue
hat-2 <=> hat
hat-2 <=> red
so we have 2 blue shoe, 1 blue hat, 1 red shoe, 1 red hat.
I cannot figure out how to find all blue shoes.
EDIT : I have found a 'solution' but it doesn't looks good :
select from Product where
in('IsRelatedToEdge')[name="blue"].size() = 1 and
in('IsRelatedToEdge')[name="shoe"].size() = 1

Answer 1

IMO, the power of OrientDB lies in the graph abilities, and queries on a table/index do not really leverage this. I feel the best way to do this query is to get the shoe criterion, then get all of the products that have an edge to the criterion. From those products (ie all the shoes), you can now filter for ones that also have an edge to the blue criterion. One way to write this is as follows...
select *
from (select expand(both('IsRelatedToEdge')) from Criterion where name = 'Shoe')
let $blue_criterion = (select from Criterion where name = 'Blue')
where both('IsRelatedToEdge') contains $blue_criterion[0]
Taking the above thought process further though, you could consider rearranging your data for better/easier querying. For example, you could make a Hat and Shoe class that are both subclasses of Product. That way to query on shoes, you query against the Shoe vertex class only. Similarly, you can make different criterion subclass, such as Color. To get blue shoes with such a config, the query would like the following...
select *
from Shoes
let $blue_criterion = (select from Color where name = 'Blue')
where both('IsRelatedToEdge') contains $blue_criterion[0]
You could even make more specific edges to take this a step further.

Answer 2

After studying neRok'solutions, i came at this solutions:
select expand($result)
let
$crit1 = (select expand(out('IsRelatedToEdge')) from Criterion where name='blue'),
$crit2 = (select expand(out('IsRelatedToEdge')) from Criterion where name='shoe'),
$result = intersect($crit1, $crit2)
With this kind of query, I can add another criterion.
Imagine if we have anotehr criterion named adidas and i want to have all blue adidas shoes :
select expand($result)
let
$crit1 = (select expand(out('IsRelatedToEdge')) from Criterion where name='blue'),
$crit2 = (select expand(out('IsRelatedToEdge')) from Criterion where name='shoe'),
$crit3 = (select expand(out('IsRelatedToEdge')) from Criterion where name='adidas'),
$result = intersect($crit1, $crit2, $crit3)