ZIO LMDB simple example for scala-2 / published by https://github.com/dacr/code-examples-manager #1c3bed7d-d01d-422d-b299-5c1fa03c5294/858c27809af102e84594f3bf52bcfa5f0397f15b

zio-lmdb-basic-scala2.sc

// summary : ZIO LMDB simple example for scala-2
// keywords : scala, zio, lmdb, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 1c3bed7d-d01d-422d-b299-5c1fa03c5294
// created-on : 2023-03-25T11:47:27+01:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala 2.13.16
//> using dep fr.janalyse::zio-lmdb:1.8.4
//> using javaOpt --add-opens java.base/java.nio=ALL-UNNAMED --add-opens java.base/sun.nio.ch=ALL-UNNAMED
// ---------------------

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

case class Record(uuid: UUID, name: String, age: Int, addedOn: OffsetDateTime)
object Record {
  implicit val jsonCodecRecord: JsonCodec[Record] = DeriveJsonCodec.gen
}

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

  val collectionName = "examples"
  val example        = for {
    examples  <- LMDB.collectionCreate[Record](collectionName, failIfExists = false)
    recordId  <- Random.nextUUID
    dateTime  <- Clock.currentDateTime
    record     = Record(recordId, "John Doe", 42, dateTime)
    _         <- examples.upsertOverwrite(recordId.toString, record)
    gotten    <- examples.fetch(recordId.toString).some
    collected <- examples.collect()
    _         <- Console.printLine(s"collection $collectionName contains ${collected.size} records")
    _         <- ZIO.foreachDiscard(collected)(record => Console.printLine(record))
    lmdb      <- ZIO.service[LMDB]
    _         <- Console.printLine("""LMDB standard tools can be used to manage the database content : sudo apt-get install lmdb-utils""")
    _         <- Console.printLine(s"""To get some statistics     : mdb_stat -s $collectionName ${lmdb.databasePath}/""")
    _         <- Console.printLine(s"""To dump collection content : mdb_dump -p -s $collectionName ${lmdb.databasePath}/""")
  } yield ()
}

SimpleExample.main(Array.empty)