分页浏览数据集而无需在MVC C＃中获取新数据集

Question

I have 3 different functions on my page. 1.) Search, 2.) Sort and 3.) Paging

I have all of this working, but I was wondering if anyone know how, or can point me somewhere that shows how to save, per user, the dataset so they can sort and page without searching again and then also when the user Searches to pull the data again.

I'm currently using MVC5, Bootstrap, and PagedList.MVC

Here's an example of what I need. I honestly am not sure how to or even if I should cache the data, but it seems like I would want to as this data changes regularly (they are events from a DB) and I'd like the user to work with the dataset they searched and not with a new dataset every time they page or sort.

private List<Models.EventItem> events = null;

[HttpPost]
public ActionResult ViewLogs(ViewModels.ViewLogs model)
{
    if (model.ActionPerformed == "search")
    {
        // it was a search, so let's pull new events in.
        events = Business.Events.GetEvents(GetCurrentSearchParameters(model));
    }

    if (model.ActionPerformed == "sort")
    {
        events = null // need to grab events from the cached dataset?
        // then need to perform the sort on the cached dataset.
    } 

    if (model.ActionPerformed == "page")
    {
        events = null // need to grab events from the cached dataset?
    }

    model.EventItems = events.ToPagedList(model.CurrentPage, model.PageSize);
    return View("ViewLogs", model);
}

[HttpGet]
public ActionResult ViewLogs()
{
    // ViewLogs (Get) will take defaults instead.
    ViewModels.ViewLogs model = new ViewModels.ViewLogs();

    events = Business.Events.GetEvents(GetCurrentSearchParameters(model));
    model.EventItems = events.ToPagedList(model.CurrentPage, model.PageSize);

    return View(model);
}

Answer 1

Based on the comments under my question, you can go about this 2 ways. The not-so-great way, but works is using Session to save the data and conditionally populate it.

What I've done research on is to actually use SQL to do the paging. In SQL you set something up similar to this which will give you total row count, total page count, and then whatever page worth of data. From what I understand, especially dealing with large chunks of data, this can save a massive amount of time. Thanks to all for putting me on the right track.

BEGIN
DECLARE @fromDate DATETIME = DATEADD(d, -30, GETUTCDATE()) 
DECLARE @page INT = 1
DECLARE @perPage INT = 25
DECLARE @totalRows INT = 0
DECLARE @totalPages INT = 0
SET NOCOUNT ON
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED
   --
   SELECT @totalRows = COUNT(*)
   FROM 
          dbo.[Events] a
   WHERE
          a.[EventTime] >= @fromDate
   ;
   --
   BEGIN TRY
          SET @totalPages = CEILING(@totalRows / @perPage); 
   END TRY
   BEGIN CATCH
          SET @totalPages = 0
   END CATCH
   --
   SELECT @totalRows AS [TotalRows], @totalPages AS [TotalPages];
   --
   --
   SELECT
          a.[EventTime],
          a.[Column1],
          a.[Column2]
   FROM 
          dbo.[Events] a
   WHERE
          a.[EventTime] >= @fromDate
   ORDER BY 
          a.[EventTime] DESC
          OFFSET (@page * @perPage) ROWS
          FETCH NEXT @perPage ROWS ONLY
   ;
END

There's a pretty in-depth article on it here: http://sqlperformance.com/2015/01/t-sql-queries/pagination-with-offset-fetch