private string CreatePagging(FilterParameters filterParameters)
{
var pageData = PageDataExtensions.GetPageData(filterParameters.PageSize, filterParameters.CurrentPage);
if (pageData.skip >= 0)
{
return($"OFFSET {pageData.skip} ROWS FETCH NEXT {pageData.take} ROWS ONLY");
}
return(string.Empty);
}
public async Task <PagedResult <TFilterableEntity> > FilterAsync(DbContext context, IResourceMandatoryPredicateFactory <TEntity, TKey> mandatoryPredicateFactory, FilterParameters filterParameters)
{
var mandatoryPredicate = mandatoryPredicateFactory.GetMandatoryPredicates();
var predicate = LinqKit.PredicateBuilder.New <TEntity>(true);
foreach (var filter in filterParameters.Statements)
{
ISpecification <TEntity> specification = Create(filter);
if (specification == null)
{
continue;
}
if (filter.LogicalOperator == FilterLogicalOperators.Or)
{
predicate.Or(specification.IsSatisfiedBy());
}
else
{
predicate.And(specification.IsSatisfiedBy());
}
}
var count = await context.Set <TEntity>().AsExpandable().Where(mandatoryPredicate).Where(predicate).LongCountAsync();
var entityQuery = context.Set <TEntity>().AsQueryable();
if (_parameters.IncludeProperties != null)
{
foreach (var includedProperty in _parameters.IncludeProperties)
{
entityQuery = entityQuery.Include(includedProperty);
}
}
var query = entityQuery.AsExpandable().Where(mandatoryPredicate).Where(predicate);
if (!string.IsNullOrWhiteSpace(filterParameters.OrderBy))
{
var sortOrder = filterParameters.OrderKind == OrderKind.Asc? ListSortDirection.Ascending: ListSortDirection.Descending;
var orderByColumn = filterParameters.OrderBy.ToLower();
if (_parameters.SortFieldsMaping.ContainsKey(orderByColumn))
{
orderByColumn = _parameters.SortFieldsMaping[orderByColumn];
}
query = query.OrderBy(orderByColumn, sortOrder);
}
var pageData = PageDataExtensions.GetPageData(filterParameters.PageSize, filterParameters.CurrentPage);
if (pageData.skip >= 0)
{
query = query.Skip(pageData.skip).Take(pageData.take);
}
TFilterableEntity[] entities;
if (_parameters.DirectProject)
{
entities = await _mapper.ProjectTo <TFilterableEntity>(query).ToArrayAsync();
}
else
{
var queryEntities = await query.ToArrayAsync();
entities = _mapper.Map <TFilterableEntity[]>(queryEntities);
}
return(new PagedResult <TFilterableEntity>(count, entities));
}