Hi, 

if this is from voyage, then is a complicated query, because it is storing a reference to a second root. 
Let���s say you have an object a1 who is an instance of A and an object b1 who is an instance of B. 

b := B new.

a := A new
data1: 42;
data2: ���something���;
refB: b.

which means what you want, in plain Pharo would be something like this: 

aCollectionOfA select: [ :each | each refB = b ].

but since you want to use Voyage, I guess you want to execute the query *in mongo* (to avoid loading all instances of A into memory).

So, in voyage you need to do it in some hack way: 

B selectOne: [ :each | ��� ].
A selectMany: [  :each | (each at: ���refB.__id���) = b voyageId ].

this will solve your problem, I guess. 

Esteban

ps: this is hacky because what in general you do with this kind of structures is to keep a list of A in B, along with your list of B in A (that means, you define a many-to-many relationship)




On 22 Nov 2016, at 11:42, Asbath Sama biyalou via Pharo-users <pharo-users@lists.pharo.org> wrote:


From: Asbath Sama biyalou <asamabiyalou@yahoo.com>
Subject: Rest Services with pharo objects as parameters
Date: 22 November 2016 at 11:42:25 GMT+1
To: Pharo users users <pharo-users@lists.pharo.org>


Hello Everybody.

I have two classes ClassA(data1 data2 ref_ClassB) ClassB (data3 data4).

I want to get list of classA where ref_ClassB = ClassB. I don't know how
to do my url in order

to sent ClassB as a parameter of the service. I am using Pharo 4.0 with
Voyage-Mongo.