def testDistinctManyColumns = {
    case class AA(from: String, to: String, data: Int)
    case class T(table: String)(tag: Tag) extends Table[AA](tag, table) {
      def from = column[String]("from")
      def to = column[String]("to")
      def data = column[Int]("data")
      def * = (from, to, data).mapTo[AA]
    }
    val ts = TableQuery(T("t1"))
    val q2 = ts.distinctOn(t => (t.to, t.from)).sortBy(t => (t.to, t.from, t.data))
    val values = Seq(
      AA("from1", "to2", 1),
      AA("from1", "to1", 1),
      AA("from1", "to2", 11),
    )
    DBIO.seq(
      ts.schema.createIfNotExists,
      ts ++= values,
      q2.result.map(_ shouldBe Vector(
        AA("from1", "to1", 1),
        AA("from1", "to2", 1),
      )),
//      DBIO.failed(new Exception)
    )
  }