Slick: Boolean values

// 1. Let's add some data with ambiguous Boolean values (-1, 0, 1, 2)
INSERT INTO `faculty` (`name`, `isArts`) VALUES
  ('mathematics', 0),
  ('biologic', 1),
  ('physics', 0),
  ('phylology', 2),
  ('historical', -1);



// 2. Now create a DAO
import javax.inject.Inject
import scala.concurrent.Future

import play.api.db.slick.{DatabaseConfigProvider, HasDatabaseConfigProvider}
import play.db.NamedDatabase
import slick.jdbc.JdbcProfile
import slick.lifted.ProvenShape

case class Faculty(facultyId: Option[Long], name: String, isArts: Boolean)

class FacultyDao @Inject() (
    @NamedDatabase("students") val dbConfigProvider: DatabaseConfigProvider
  ) extends HasDatabaseConfigProvider[JdbcProfile] {

  import profile.api._

  private class FacultyTable(tag: Tag) extends Table[Faculty](tag, "faculty") {
    def facultyId: Rep[Long] = column[Long]("faculty_id", O.PrimaryKey, O.AutoInc)
    def name: Rep[String] = column[String]("name")
    def isArts: Rep[Boolean] = column[Boolean]("isArts")

    override def * : ProvenShape[Faculty] = (facultyId.?, name, isArts) <> (Faculty.tupled, Faculty.unapply)
  }

  private lazy val table = TableQuery[FacultyTable]

  def getAll: Future[Seq[Faculty]] = {
    val query = table.result
    println(query.statements.mkString)
    db.run(query)
  }
}



// 3. Now inject this DAO to our controller:
import javax.inject.Inject
import scala.concurrent.ExecutionContext
import play.api.mvc._
import dao.FacultyDao

class TestController @Inject()(
    facultyDao: FacultyDao, cc: ControllerComponents)(implicit ec: ExecutionContext) extends AbstractController(cc) {

  // add to routes file: GET    /testBoolean    controllers.TestController.testBoolean
  def testBoolean: Action[AnyContent] = Action.async {
    facultyDao.getAll map { lst =>
      Ok(s"Result:\n${lst.mkString("\n")}")
    }
  }
}



// 4. Call endpoint and see the output:
// select `faculty_id`, `name`, `isArts` from `faculty`
//
// Result:
// Faculty(Some(1),mathematics,false)
// Faculty(Some(2),biologic,true)
// Faculty(Some(3),physics,false)
// Faculty(Some(4),phylology,true)
// Faculty(Some(5),historical,true)

// Summary: Boolean is a C-style: 0 = false, !0 = true