Insertion into scylladb table using phantom library in scala not working

Question

I'm new to ScyllaDB, and trying to perform CRUD operations using phantom library in scala. First I've made 3-node cluster and its running fine.

Datacenter: DC1
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address     Load       Tokens       Owns    Host ID                               Rack
UN  172.19.0.3  1.1 MB     256          ?       1db1e9a6-8e99-4d7c-b086-f169b4619e16  Rack1
UN  172.19.0.2  1.14 MB    256          ?       f6e6ef6b-7ec5-4a59-aaa0-975eac039794  Rack1
UN  172.19.0.4  1.14 MB    256          ?       9aac568d-bafb-4d9b-b2aa-8a0bfd64ef4f  Rack1

Then I made keyspace with name "user_keyspace", and create table "users" inside it. Now I'm trying to insert data using phantom library in scala. User Model:

case class User(userID: Int, firstName: String, lastName: String)

Users class, which I extend with Table[]:

import com.outworkers.phantom.dsl._

abstract class Users extends Table[Users, User] {
  override def tableName: String = "users"

  object UserID extends IntColumn with PartitionKey {
    override def name: String = "user_id"
  }

  object FirstName extends IntColumn {
    override def name: String = "first_name"
  }

  object LastName extends IntColumn {
    override def name: String = "last_name"
  }
}

UsersDatabase Class:

import com.outworkers.phantom.dsl._

class UsersDatabase(override val connector: CassandraConnection) extends Database[UsersDatabase](connector) {
  object users extends Users with Connector
}

UsersOperations Class:

import com.outworkers.phantom.dsl._
import scala.concurrent.Future

class UserOperations(db: UsersDatabase) {

  import db.{session, space}

  def insertUser(user: User): Future[ResultSet] =
    db.users.store(user).future()
}

Main Class:

import com.outworkers.phantom.dsl._
import scala.util._

object App extends App {
  private val connection: CassandraConnection =
    ContactPoints(List("172.19.0.3", "172.19.0.2", "172.19.0.4"))
      .keySpace("user_keyspace")

  private val db = new UsersDatabase(connection)
  private val userOperations = new UserOperations(db)

  userOperations.insertUser(User(2,"Ali","Hassan")).onComplete{
    case Success(value) =>
      println("Users: " + value)
      db.shutdown()

    case Failure(exception) =>
      println("Exception: " + exception)
      db.shutdown()
  }
}

build.sbt file:

ThisBuild / version := "0.1.0-SNAPSHOT"

ThisBuild / scalaVersion := "2.13.1"

lazy val root = (project in file("."))
  .settings(
    name := "my_scylladb_app"
  )

libraryDependencies += "com.outworkers" %% "phantom-dsl" % "2.59.0"
libraryDependencies += "org.scala-lang" % "scala-reflect" % "2.13.10"
libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.4.6"

When I run this code, it gives error:

[error] /home/zaryab/IdeaProjects/my_scylladb_app/src/main/scala/UserOperations.scala:14:19: could not find implicit value for parameter sg: com.outworkers.phantom.macros.SingleGeneric.Aux[User,Repr,HL,Out] (The type you're trying to store User should match either Repr or HL)
[error]     db.users.store(user).future()
[error]                   ^
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

Please help me to remove this error.

Answer 1

If you define the class as case class User(userID: Int, firstName: String, lastName: String) then

object FirstName extends IntColumn {
  override def name: String = "first_name"
}

object LastName extends IntColumn {
  override def name: String = "last_name"
}

must be

object FirstName extends StringColumn {
  override def name: String = "first_name"
}

object LastName extends StringColumn {
  override def name: String = "last_name"
}

This was the error.

---

By the way, it's better to use the same version of scala-reflect, scala-compiler as scalaVersion. So

ThisBuild / scalaVersion := "2.13.1"
libraryDependencies += "org.scala-lang" % "scala-reflect" % "2.13.10"

should be better either

ThisBuild / scalaVersion := "2.13.10"
libraryDependencies += "org.scala-lang" % "scala-reflect" % "2.13.10"

or

ThisBuild / scalaVersion := "2.13.1"
libraryDependencies += "org.scala-lang" % "scala-reflect" % "2.13.1"

It's better to write

libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value

or even

libraryDependencies += scalaOrganization.value % "scala-reflect" % scalaVersion.value

to avoid such confusion. Actually, you do not seem to use scala-reflect at all.