scala - MongoDB cross-collection query with casbah -

i have 2 collections follwoing,

customers:   {id: 1, name: "foo"}   {id: 2, name: "bar"}   {id: 3, name: "baz"}  flags:   {cid: 1}   {cid: 3} 

then retrieving customers flag on

db.customers.find({id: {$in: db.flags.distinct("cid", {})}}) 

on shell works, can't same using casbah, since casbah not seem support querying function call or local variable.

of course can in casbah - remember db.flags.distinct returns iterable should converted implicitly list use in $in. heres test example you:

import com.mongodb.casbah.imports._ val db = mongoclient()("casbahtest") val customers = db("customers") val flags = db("flags")  customers.drop() flags.drop()  // add customers customers += mongodbobject("_id" -> 1, "name" -> "foo") customers += mongodbobject("_id" -> 2, "name" -> "bar") customers += mongodbobject("_id" -> 3, "name" -> "baz")  // add flags flags += mongodbobject("cid" -> 1) flags += mongodbobject("cid" -> 3)   // query // in js: db.customers.find({id: {$in: db.flags.distinct("cid", {})}})  // long hand: customers.find(mongodbobject("_id" -> mongodbobject("$in" -> flags.distinct("cid"))))  // using casbahs query dsl build mongodbobject: customers.find("_id" $in flags.distinct("cid"))