API Before IAsyncenumerable changes

1_DapperQuery

    // Using Dapper;

    public async Task<IEnumerable<Item>> GetItems(int id)
    {
        var reader = await _connection.QueryMultipleAsync(getItemsSql,
           param: new
           {
               Id = id
           });

        var idFromDb = (await reader.ReadAsync<int?>().ConfigureAwait(false)).SingleOrDefault();
        if (idFromDb == null)
        {
           return null;
        }

        var items = await reader.ReadAsync<Item>(buffered: false).ConfigureAwait(false);

        return Stream(reader, items);
    } 

    private IEnumerable<Item> Stream(SqlMapper.GridReader reader, IEnumerable<Item> items)
    {
        using (reader)
        {
            foreach (var item in items)
            {
                yield return item;
            }
        }     
    }

2_GetItemsController

  public async Task<IActionResult> GetItems(int id)
  {
      var items = await _query.GetItems(id);
      return Ok(Stream(items);
  }

  private IEnumerable<ItemDto> Stream(IEnumerable<Item> items)
  {
      foreach (var item in items)
      {
          yield return GetItemDto(item);
      }
  }
  
  private static ItemDto GetItemDto(Item item)
  {
      return new ItemDto
      {
         //  Convert Item to ItemDto
      };
  }