protected def locationGroupLinkTable: Query[(Rep[LocationGroupId], Rep[LocationId]), (LocationGroupId, LocationId), Seq] = {

    import common.Contexts.simpleDbLookups
    import profile.api._

    val rawData: Seq[LocationGroupLink] = Await.result(locationGroupLinkRepository.all, Duration.Inf)

    val tableRows: Seq[Query[(ConstColumn[LocationGroupId], ConstColumn[LocationId]), (LocationGroupId, LocationId), Seq]] = {
      rawData.map { link =>
        Query(link.groupId, link.merchantId)
      }
    }

    val subQuery: String = rawData.map { link =>
      (link.groupId.value, link.merchantId.value)
    }.map { case (locationGroupId, merchantId) =>
        s"SELECT $locationGroupId AS L, $merchantId AS M FROM DUAL"
    }.mkString(" UNION ")

    val sql: String = s"SELECT L, M FROM ($subQuery)"

    val q: SqlStreamingAction[Vector[(LocationGroupId, LocationId)], (LocationGroupId, LocationId), Effect] = {
      sql"""#$sql""".as[(LocationGroupId, LocationId)]
    }

    q
  }