public static Option <Page <T> > GetPage <T>(this Microsoft.EntityFrameworkCore.DbSet <T> List, int Page_index, int page_size, Func <T, object> order_by_selector, Func <T, bool> filter_by_selector, bool descending)
where T : class
{
IOrderedEnumerable <T> resTMP;
if (descending)
{
resTMP = List
.Where(filter_by_selector)
.OrderByDescending(order_by_selector);
}
else
{
resTMP = List
.Where(filter_by_selector)
.OrderBy(order_by_selector);
}
T[] res = resTMP
.Skip(Page_index * page_size)
.Take(page_size)
.ToArray();
if (res == null || res.Length == 0)
{
return(new Empty <Page <T> >());
}
var tot_items = resTMP.Count();
var tot_pages = tot_items / page_size;
if (tot_items < page_size)
{
tot_pages = 1;
}
return(new Some <Page <T> >(new Page <T>()
{
Index = Page_index, Items = res, TotalPages = tot_pages
}));
}
public static Page <T> GetPage <T>(this Microsoft.EntityFrameworkCore.DbSet <T> list, int page_index, int page_size, Func <T, object> order_by_selector, bool descending = false, Func <T, bool> filter_by_predicate = null)
where T : class
{
var res = list.OrderBy(order_by_selector)
.Skip(page_index * page_size)
.Take(page_size)
.ToArray();
if (descending == true)
{
res = list.OrderByDescending(order_by_selector)
.Skip(page_index * page_size)
.Take(page_size)
.ToArray();
}
var tot_items = list.Count();
if (descending == true)
{
if (filter_by_predicate != null)
{
res = list.Where(filter_by_predicate)
.OrderByDescending(order_by_selector)
.Skip(page_index * page_size)
.Take(page_size)
.ToArray();
tot_items = list.Where(filter_by_predicate)
.Count();
}
}
else
{
if (filter_by_predicate != null)
{
res = list.Where(filter_by_predicate)
.OrderBy(order_by_selector)
.Skip(page_index * page_size)
.Take(page_size)
.ToArray();
tot_items = list.Where(filter_by_predicate)
.Count();
}
}
if (res == null || res.Length == 0)
{
return(null);
}
var tot_pages = tot_items / page_size;
if (tot_items < page_size)
{
tot_pages = 1;
}
return(new Page <T>()
{
index = page_index, items = res, totalPages = tot_pages
});
}
public IActionResult Get(int id)
{
return(Ok(_bikes.Where(p => p.Id == id).FirstOrDefault()));
}
/// <summary>
/// Find the entity for the specified predicate.
/// </summary>
/// <param name="predicate">The predicate.</param>
/// <returns></returns>
public IEnumerable <T> Find(Expression <Func <T, bool> > predicate)
{
return(_dbSet.Where(predicate));
}
