public static SelectExpression RemoveOrderExpression(this SelectExpression select, OrderExpression ordering)
{
if ((select.OrderBy != null) && (select.OrderBy.Count > 0))
{
List <OrderExpression> orderBy = new List <OrderExpression>(select.OrderBy);
orderBy.Remove(ordering);
return(select.SetOrderBy(orderBy));
}
return(select);
}
public static SelectExpression AddOrderExpression(this SelectExpression select, OrderExpression ordering)
{
List <OrderExpression> orderBy = new List <OrderExpression>();
if (select.OrderBy != null)
{
orderBy.AddRange(select.OrderBy);
}
orderBy.Add(ordering);
return(select.SetOrderBy(orderBy));
}
protected override Expression VisitSelect(SelectExpression selectExpression)
{
selectExpression = (SelectExpression)base.VisitSelect(selectExpression);
if (((selectExpression.Skip != null) && (selectExpression.Take != null)) && (selectExpression.OrderBy.Count > 0))
{
Expression skip = selectExpression.Skip;
Expression take = selectExpression.Take;
Expression expression3 = PartialEvaluator.Eval(Expression.Add(skip, take));
selectExpression = selectExpression.SetTake(expression3).SetSkip(null);
selectExpression = selectExpression.AddRedundantSelect(this.language, new TableAlias());
selectExpression = selectExpression.SetTake(take);
selectExpression = (SelectExpression)OrderByRewriter.Rewrite(this.language, selectExpression);
IEnumerable <OrderExpression> orderBy = from ob in selectExpression.OrderBy select new OrderExpression((ob.OrderType == OrderType.Ascending) ? OrderType.Descending : OrderType.Ascending, ob.Expression);
selectExpression = selectExpression.SetOrderBy(orderBy);
selectExpression = selectExpression.AddRedundantSelect(this.language, new TableAlias());
selectExpression = selectExpression.SetTake(Expression.Constant(0));
selectExpression = (SelectExpression)OrderByRewriter.Rewrite(this.language, selectExpression);
IEnumerable <OrderExpression> enumerable2 = from ob in selectExpression.OrderBy select new OrderExpression((ob.OrderType == OrderType.Ascending) ? OrderType.Descending : OrderType.Ascending, ob.Expression);
selectExpression = selectExpression.SetOrderBy(enumerable2);
selectExpression = selectExpression.SetTake(null);
}
return(selectExpression);
}