def select_list(statement, build_arg = nil)
    select(statement, build_arg).collect { |row| row.at(0) }
  end
def select_list(statement, build_arg = nil)
    select(statement, build_arg).collect { |row| row.at(0) }
  end
Returns an array of the first (and typically, the only) field of every row in the result set.