Doobie

We provide tracing capabilities for Doobie which is a functional JDBC driver. We wrap the Transactor as well as hijack the underlying PreparedStatement in order to provide detailed debugging information.

Here is an example of how to set it up:

import doobie.*
import doobie.syntax.all.*
import io.kaizensolutions.trace4cats.zio.extras.ZTracer
import io.kaizensolutions.trace4cats.zio.extras.doobie.TracedTransactor
import zio.*
import zio.interop.catz.*

val transactorLayer = ZLayer.succeed(
  Transactor.fromDriverManager[Task](
    driver = "org.postgresql.Driver",
    url = "jdbc:postgresql:postgres",
    user = "postgres",
    password = "postgres",
    logHandler = None
  )
)
val tracedTransactorLayer: URLayer[ZTracer, Transactor[Task]] =
  ZLayer.service[ZTracer] ++ transactorLayer >>> TracedTransactor.default

case class City(id: Int, name: String, countryCode: String, district: String, population: Int)

val program: RIO[ZTracer, List[City]] = 
  ZIO.serviceWithZIO[Transactor[Task]] { xa =>
    val startId = 1810
    val endId   = 1830
    
    sql"select id, name, countryCode, district, population from city where id > $startId and id < $endId"
      .query[City]
      .stream
      .transact(xa)
      .debug()
      .compile
      .toList
  }
  .provideSome[ZTracer](tracedTransactorLayer)

Here is an example of the trace that is generated:

Have a look at the example for a better understanding.