public async Task GetItemsOffsetPaging(PagingOffsetArgs args)
{
var watch = System.Diagnostics.Stopwatch.StartNew();
var query = _demoDbContext.Items;
_itemsOffsetPagingLoading.OnNext(true);
_itemsOffsetPaging.OnNext(new PagingOffsetData
{
Items = await query.OrderBy(x => x.CreateDate)
.Skip(args.PageIndex * args.PageSize)
.Take(args.PageSize).ToListAsync(),
Total = await query.CountAsync()
});
watch.Stop();
_execTime.OnNext($"Execution Time: {watch.ElapsedMilliseconds} ms");
_itemsOffsetPagingLoading.OnNext(false);
}
public async Task GetItemsOffsetPagingOptimized(PagingOffsetArgs args)
{
var watch = System.Diagnostics.Stopwatch.StartNew();
var query = _demoDbContext.Items;
Expression <Func <Item, bool> > whereExp = (Item item) => query
.OrderBy(x => x.CreateDate)
.Select(y => y.Id)
.Skip(args.PageIndex * args.PageSize)
.Take(args.PageSize).Contains(item.Id);
_itemsOffsetPagingOptLoading.OnNext(true);
_itemsOffsetPagingOpt.OnNext(new PagingOffsetData
{
Items = await query.Where(whereExp).ToListAsync(),
Total = await query.CountAsync()
});
watch.Stop();
_execTime.OnNext($"Execution Time: {watch.ElapsedMilliseconds} ms");
_itemsOffsetPagingOptLoading.OnNext(false);
}
