scala: czytanie tabel

  classOf[org.postgresql.Driver]
  val table = "dbo.countries"

  override def findAll: Seq[CountriesDto] = {
    var rows = ListBuffer[CountriesDto]()
    try {
      val sql = "SELECT * FROM ?"
      val stmt = conn.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY)
      stmt.setString(1, table)
      val rs = stmt.executeQuery()
      while (rs.next) {
        rows += CountriesDto(rs.getString(0), rs.getString(1), rs.getBoolean(2))
      }
    }
    finally {
      conn.close()
    }
    rows.toSeq
  }

spark.read
  .jdbc("jdbc:postgresql:dbserver", table, conn)

   class Managers(tag: Tag) extends Table[(Int, String, String)](tag, "managers") {
    def id = column[Int]("id")
    def name = column[String]("name")
    def department = column[String]("department")
    def * = (id, name, department)
  }
  lazy val managers = TableQuery[Managers]

  class Employees(tag: Tag) extends Table[(Int, String, Int)](tag, "employees") {
    def id = column[Int]("id")
    def name = column[String]("name2")
    def manager = column[Int]("manager")
    def * = (id, name, manager)

    // A convenience method for selecting employees by department
    def departmentIs(dept: String) = manager in managers.filter(_.department === dept).map(_.id)
  }
  lazy val employees = TableQuery[Employees]

  def managersQuery = for(m <- managers filter { _.department === "IT" }) yield (m.id, m.name)

  def employeesQuery = for(e <- employees filter { _.departmentIs("IT") }) yield (e.id, e.name)

  val managersData = Seq(
    (1, "Peter", "HR"),
    (2, "Amy", "IT"),
    (3, "Steve", "IT")
  )

  val employeesData = Seq(
    (4, "Jennifer", 1),
    (5, "Tom", 1),
    (6, "Leonard", 2),
    (7, "Ben", 2),
    (8, "Greg", 3)
  )

  def testBasicUnions = {

    val q1 = managersQuery
    val q2 = employeesQuery
    val q3 = (q1 union q2).sortBy(_._2.asc)
    val q4 = managers.map(_.id)
    val q4b = q4 union q4
    val q4c = q4 union q4 union q4
    val q5 = managers.map(m => (m.id, 0)) union employees.map(e => (e.id, e.id))

    (for {
      _ <- (managers.schema ++ employees.schema).create
      _ <- managers ++= managersData
      _ <- employees ++= employeesData
      _ <- mark("q1", q1.result).map(r => r.toSet shouldBe Set((2,"Amy"), (3,"Steve")))
      _ <- mark("q2", q2.result).map(r => r.toSet shouldBe Set((7,"Ben"), (8,"Greg"), (6,"Leonard")))
      _ <- mark("q3", q3.result).map(_ shouldBe List((2,"Amy"), (7,"Ben"), (8,"Greg"), (6,"Leonard"), (3,"Steve")))
      _ <- mark("q4b", q4b.result).map(r => r.toSet shouldBe Set(1, 2, 3))
      _ <- mark("q4c", q4c.result).map(r => r.toSet shouldBe Set(1, 2, 3))
      _ <- mark("q5", q5.result).map(r => r.toSet shouldBe Set((7,7), (6,6), (2,0), (4,4), (3,0), (8,8), (5,5), (1,0)))
    } yield ()) andFinally (managers.schema ++ employees.schema).drop
  }

  def managersQuery = for(m <- managers filter { _.department === "IT" }) yield (m.id, m.name)
  def employeesQuery = for(e <- employees filter { _.departmentIs("IT") }) yield (e.id, e.name)
  val q1 = managersQuery
  val q2 = employeesQuery
  val q3 = (q1 union q2).sortBy(_._2.asc)