Orientdb: Filter on properties of nested relationships

[snig-b]

I have a query like the following:

SELECT $a.b, $a.c, $a.out('r3').e, $a.out('r3').f from classD
LET $a=out('r').in('r2')
WHERE field='abc' and $a.out_r3.some_field = 'some_value' OR ( $a.some_field IS NULL)

As is evident I use --> out('r3') syntax to access the fields of the attached vertex, and out_r3 syntax to access fields of the Edge.

These syntax work fine in projections but they do not work in the WHERE clause, because the value in $a.out_r3 on return is a collection of all values. I thought the UNWIND operator might help me there but I am not sure.

Example graph for this condition is :

A ---> D <--- C ---> E

I am accessing D, C, E via A's relationships and want to filter on the properties of relationships connecting A & D and C & D.

All changes in syntax are failing, it just returns 0 records.
How to I filter on nested graph relationships?

[luigidellaquila]

Hi Snigdha,

have you tried with this?

$a.out_r3.some_field contains "some value"

or even better

$a.out("r3").some_field contains "some value"

Luigi

2015-05-20 14:17 GMT+02:00 Snigdha Batra [email protected]:

I have a query like the following:

SELECT $a.b, $a.c, $a.out('r3').e, $a.out('r3').f from classD
LET $a=out('r').in('r2')
WHERE field='abc' and $a.out_r3.some_field = 'some_value' OR (
$a.some_field IS NULL)

As is evident I use --> out('r3') syntax to access the fields of the
attached vertex, and out_r3 syntax to access fields of the Edge.

These syntax work fine in projections but they do not work in the WHERE
clause, because the value in $a.out_r3 on return is a collection of all
values. I thought the UNWIND operator might help me there but I am not sure.

Example graph for this condition is :

A ---> D <--- C ---> E

I am accessing D, C, E via A's relationships and want to filter on the
properties of relationships connecting A & D and C & D.

All changes in syntax are failing, it just returns 0 records.
How to I filter on nested graph relationships?

—
Reply to this email directly or view it on GitHub
https://github.com/orientechnologies/orientdb/issues/4186.

[snig-b]

Hey Luigi

Thanks for the response.

Yes I have, that covers a very small use case of checking whether a string type data is present in the resulting collection. That is a condition on the whole record returning me the arrays.

My requirement is to apply the filters before forming the collections.

That is if $a.out("r3") is returning me ['#12:456','#13:4667']

OR $a.out("r3").some_field is returning me ["some_value",..]

Then I want to apply a where clause that let's me choose whether "some_value" containing record would be returned in the result or not. i.e Remove the '#12:456' relationship altogether..

Similar functionality exists in another GraphDB example in MATCH query -

MATCH (a:A)--[b:B]-->(c:C)--[e:E]-->(f:A)
WHERE e.some_field > b.some_field
RETURN a,b,c

The resulting records would not contain that combination that does not satisfy the where condition.

[snig-b]

Any update on this?

[luigidellaquila]

Ok, I got the problem now.
Right now it's hard to do this with SQL queries, this is why we are implementing a new MATCH statement (https://github.com/orientechnologies/orientdb-docs/blob/master/SQL-Match.md) with the same philosophy of the query you posted as an example

[luigidellaquila]

Hi @snig-b

V 2.2 is out with the new MATCH statement

http://orientdb.com/docs/last/SQL-Match.html

It was designed specifically to manage this kind of queries.

I'm closing this issue, please feel free to reopen if you need help on that

Thanks

Luigi