Paging
For paged access to data, Marten provides ToPagedList
and ToPagedListAsync
extension methods on IQueryable<T>
.
cs
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
cs
var pageNumber = 2;
var pageSize = 10;
var pagedList = await theSession.Query<Target>().ToPagedListAsync(pageNumber, pageSize);
If you want to create you own paged queries, just use the Take()
and Skip()
Linq operators in combination with Stats()
cs
[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);
}
For the sake of completeness, the SQL generated in the operation above by Marten would be:
sql
select d.data, d.id, count(*) 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.