Query Examples

This pages collects example of query from users. Feel free to add your own use case and query to help further users.

How to ask the graph what relationships exist between two vertices? In my case I have two known ‘Person’ nodes each connected via a ‘member_of’ edge to a shared ‘Organization’ node. Each ‘Person’ is also a ‘member_of’ other ‘Organization’s. 

  1. select intersect(out('member_of').org_name) from
  2.  Person where name in ["nagu", "rohit"]

This example shows how to form where clause in order to query/ filter based on properties of connected vertices.

DocElem and Model are subclasses of V and hasModel of E.

  1.     insert into DocElem set uri = 'domain.tdl', type = "paragraph"
  2.     insert into Model set hash = '0e1f', model = "hello world"
  3.     create edge hasModel from #12:2738 to #13:2658

User wishes to query those vertices filtering on certain properties of DocElem and Model.

To fetch the Model vertices where DocElem.type = “paragraph” and connected vertex Model has the property model like ‘%world%’

  1.     select from (select expand(out('hasModel')) from DocElem where 
  2.       type = "paragraph") where model like "%world%"

To find instead the DocElem vertices, use this (assuming that a DocElem is only connected to one Model):

  1.     select * from DocElem where type = "paragraph" and 
  2.       out('hasModel')[0].model like '%world%'

How to apply built-in math functions on projections? For example, to use the sum() function over 2 values returned from sub-queries using projections, the following syntax may be used:

  1.   select sum($a[0].count,$b[0].count) 
  2.     let $a = (select count(*) from e), 
  3.         $b = (select count(*) from v)

Given the following schema: Vertices are connected with Edges of type RELATED which have property count. 2 vertices can have connection in both ways at the same time.

V1—RELATED(count=17)—>V2

V2—RELATED(count=3)—>V1

Need to build a query that, for a given vertex Vn, will find all vertices connected with RELATED edge to this Vn and also, for each pair [Vn, Vx] will calculate SUM of in_RELATED.count and out_RELATED.count.

For that simple example above, this query result for V1 would be

Vertex Count
V2 20

Solution:

  1. select v.name, sum(count) as cnt from (
  2.   select if(eval("in=#17:0"),out,in) as v,count from E where (
  3.     in=#17:0 or out=#17:0)
  4.   ) order by cnt desc group by v

This was discussed in the google groups over here: “https://groups.google.com/forum/#!topic/orient-database/CRR-simpmLg“. Thanks to Andrey for posing the problem.