kotlin support native query
// 08-02-2020
fun <T:Any> String.execAndMap(transform : (ResultSet) -> T) : List<T> {
val result = arrayListOf<T>()
TransactionManager.current().exec("") { rs ->
while (rs.next()) {
result += transform(rs)
}
}
return result
}
"select u.name, c.name from user u inner join city c where blah blah".execAndMap { rs ->
rs.getString("u.name") to rs.getString("c.name")
}