lookup
fun <FROM : Any> lookup(from: MongoCollection<FROM>, localField: KProperty1<out Any, Any?>, foreignField: KProperty1<FROM, Any?>, newAs: String): Bson
fun <FROM : Any> lookup(from: MongoCollection<FROM>, localField: KProperty1<out Any, Any?>, foreignField: KProperty1<FROM, Any?>, newAs: String): Bson
Creates a $lookup pipeline stage, joining the current collection with the one specified in from using the given pipeline. If the first stage in the pipeline is a {@link Aggregates#documents(List) $documents} stage, then the {@code from} collection is ignored.
Return
the $lookup pipeline stage @mongodb.driver.manual reference/operator/aggregation/lookup/ $lookup @mongodb.server.release 3.6
Parameters
from
the collection in the same database to perform the join with.
local
the data class field from the local collection to match values against.
foreign
the data class field in the from collection to match values against.
pipeline
the pipeline to run on the joined collection.
as
the name of the new array field to add to the input documents.