Paging

For paged access to data, Marten provides ToPagedList and ToPagedListAsync extension methods on IQueryable<T>.

var pageNumber = 2;
var pageSize = 10;

var pagedList = theSession.Query<Target>().ToPagedList(pageNumber, pageSize);

// paged list also provides a list of helper properties to deal with pagination aspects
var totalItems = pagedList.TotalItemCount; // get total number records
var pageCount = pagedList.PageCount; // get number of pages
var isFirstPage = pagedList.IsFirstPage; // check if current page is first page
var isLastPages = pagedList.IsLastPage; // check if current page is last page
var hasNextPage = pagedList.HasNextPage; // check if there is next page
var hasPrevPage = pagedList.HasPreviousPage; // check if there is previous page
var firstItemOnPage = pagedList.FirstItemOnPage; // one-based index of first item in current page
var lastItemOnPage = pagedList.LastItemOnPage; // one-based index of last item in current page

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var pageNumber = 2;
var pageSize = 10;

var pagedList = await theSession.Query<Target>().ToPagedListAsync(pageNumber, pageSize);

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If you want to create you own paged queries, just use the Take() and Skip() Linq operators in combination with Stats()

[Fact]
public void can_get_the_total_in_results()
{
    var count = theSession.Query<Target>().Count(x => x.Number > 10);
    SpecificationExtensions.ShouldBeGreaterThan(count, 0);

    // We're going to use stats as an output
    // parameter to the call below, so we
    // have to declare the "stats" object
    // first
    QueryStatistics stats = null;

    var list = theSession
        .Query<Target>()
        .Stats(out stats)
        .Where(x => x.Number > 10).Take(5)
        .ToList();

    list.Any().ShouldBeTrue();

    // Now, the total results data should
    // be available
    stats.TotalResults.ShouldBe(count);
}

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For the sake of completeness, the SQL generated in the operation above by Marten would be:

sql

select d.data, d.id, count(1) OVER() as total_rows from public.mt_doc_target as d
where CAST(d.data ->> 'Number' as integer) > :arg0 LIMIT 5

The Stats() Linq operator can be used in conjunction with Include() and within batch queries. Marten does not yet support using Stats() within the compiled query.

Paging #

Paging