private IQueryable <Bucket> BuildQuery(Expression <Func <Bucket, bool> > predicate, int?limit, int?offset, Ordering <Bucket>?ordering = null)
{
if (predicate is null)
{
throw new ArgumentNullException(nameof(predicate));
}
IQueryable <Bucket> query = this.context.Set <Bucket>().Where(predicate);
if (ordering != null)
{
foreach (OrderBy orderBy in ordering)
{
string methodName = orderBy.Ascending ? nameof(Queryable.ThenBy) : nameof(Queryable.ThenByDescending);
if (orderBy == ordering.First())
{
methodName = orderBy.Ascending ? nameof(Queryable.OrderBy) : nameof(Queryable.OrderByDescending);
}
query = query.Provider.CreateQuery <Bucket>(Expression.Call(
typeof(Queryable),
methodName,
new Type[] { typeof(Bucket), KeySelectors[orderBy.PropertyName].ReturnType },
query.Expression,
Expression.Quote(KeySelectors[orderBy.PropertyName])));
}
}
if (offset != null)
{
query = query.Skip(offset.GetValueOrDefault());
}
if (limit != null)
{
query = query.Take(limit.GetValueOrDefault());
}
return(query);
}
