ZIO LMDB simple transaction example / published by https://github.com/dacr/code-examples-manager #a763b457-5b4c-4cdb-897c-23bb321ec2f9/a8e64022131ec339134c2ed4ef5665fefadddb77

zio-lmdb-basic-transaction.sc

// summary : ZIO LMDB simple transaction example
// keywords : scala, zio, lmdb, transaction, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : a763b457-5b4c-4cdb-897c-23bb321ec2f9
// created-on : 2026-02-03T08:55:25+01:00
// managed-by : https://github.com/dacr/code-people-manager
// run-with : scala-cli $file

// ---------------------
//> using scala 3.8.1
//> using dep fr.janalyse::zio-lmdb:2.3.2
//> using javaOpt --add-opens java.base/java.nio=ALL-UNNAMED --add-opens java.base/sun.nio.ch=ALL-UNNAMED
// ---------------------

import zio.*, zio.json.*, zio.lmdb.*, zio.lmdb.json.*
import java.io.File, java.util.UUID, java.time.OffsetDateTime

case class Record(uuid: UUID, name: String, age: Int, addedOn: OffsetDateTime) derives LMDBCodecJson

object SimpleExample extends ZIOAppDefault {
  override def run = example.provide(LMDB.liveWithDatabaseName("lmdb-data-basic-transaction-example"), Scope.default)

  val collectionName = "people"
  val example        = for {
    people    <- LMDB.collectionCreate[UUID, Record](collectionName, failIfExists = false)
    dateTime  <- Clock.currentDateTime
    record1   <- Random.nextUUID.map(id => Record(id, "John Doe", 42, dateTime))
    record2   <- Random.nextUUID.map(id => Record(id, "Sarah Connors", 24, dateTime))
    _         <- people.readWrite { peopleTX =>
                   peopleTX.upsertOverwrite(record1.uuid, record1) *>
                     peopleTX.upsertOverwrite(record2.uuid, record2)
                 }
    collected <- people.collect()
    _         <- ZIO.foreachDiscard(collected)(record => Console.printLine(record))
  } yield ()
}

SimpleExample.main(Array.empty)