scala mongodb IN filter use

user_3285672 0
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I have been struggling with the Filters for MongoDB in the Scala mongo Driver. I am trying to get all documents in a collection where a specific string in the document is in a list of strings. I create a list of strings in Scala and then I build the query with the IN operator:

val find3 = in(EventItem, ListDelayedItems.toList)

According to the documentation, the in has two overloaded methods:

public static <TItem> Bson in(String fieldName,
                              TItem... values)
public static <TItem> Bson in(String fieldName,
                              Iterable<TItem> values)

The problem is, I have no idea how to construct Iterable values. If I pass the values as a list of values (see the first overloaded method), 

in(EventItem, "ABCDE", "DEF", "ESO4SAP")

it works. This is what I see when I print the in operator filter

Operator Filter{fieldName='billing_event.action.resources.item', operator='$in', value=[ABCDE, DEF, ESO4SAP]}

But as soon as I try to pass a list in the second parameter to use the second overloaded method, it does not work. The list I am trying to use to filter is dynamic. I have tried scala Lists, ListBuffers, java.util.Lists but every time I use the variable like this:

in(EventItem, ListValidItems)

It stops working. I defined the ListValidItems as every collection I know, but when I see the log I see this:

Operator Filter{fieldName='billing_event.action.resources.item', operator='$in', value=[List(ABCDE, EFGH, ESO4SAP)]}

So it changed from value=[ABCDE, DEF, ESO4SAP] to value=[List(ABCDE, EFGH, ESO4SAP)] and the filter does not work.

As I mentioned, I tried a lot of different list, tried list.toIterator but nothing seems to work for converting the list data structure to a list of values TItem... or Iterable

This is the list of Imports for the mongoDB driver

import org.mongodb.scala.connection.ClusterSettings
import com.mongodb.BasicDBObject
import com.mongodb.client.model.{FindOneAndReplaceOptions, FindOneAndUpdateOptions}
import org.mongodb.scala.ServerAddress
import org.mongodb.scala._
import org.mongodb.scala.bson.{BsonDocument, conversions}
import org.mongodb.scala.model.Filters._
import org.mongodb.scala.model.Updates._

Any ideas?

Thanks!!

mongodb-query mongodb scala
2 Answers
import java.util.concurrent.TimeUnit
import org.bson.Document
import org.mongodb.scala.bson.BsonDocument
import org.mongodb.scala.bson.conversions.Bson
import org.mongodb.scala.{FindObservable, MongoClient, MongoCollection, MongoDatabase, Observer, Subscription}

val client: MongoClient = MongoClient("mongodb://127.0.0.1:27017")
val db: MongoDatabase = client.getDatabase("test")
val dbColl: MongoCollection[Document] = db.getCollection[Document]("md" + TaskContext.getPartitionId)
val ids: List[String] = List("A","B","C")  
val listStr: String = ids.map(o => "\"" + o + "\"").distinct.mkString(",")
val filterStr = """{_id:{$in:""" + s"""[$listStr]}}"""
val filterDoc: Document = Document.parse(filterStr)
val obs: FindObservable[Document] = dbColl.find(filterDoc)
val documents: Seq[Document] = Await.result(obs.toFuture(), Duration(10, TimeUnit.SECONDS))

This works.

user_105553230
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