badcommandorfilename
commented
4 years ago Just FYI, I can submit a pull request to fix this if a maintainer is happy with the proposal to have "unsorted" be the default for aggregate responses.
My suggested patch would be something like:
namespace Microsoft.AspNet.OData.Query.Expressions
{
/// <summary>
/// Represents a container class that contains properties that are grouped by using $apply.
/// </summary>
- public abstract class DynamicTypeWrapper
+ public abstract class DynamicTypeWrapper : IComparable
{
/// <summary>
/// Gets values stored in the wrapper
/// </summary>
public abstract Dictionary<string, object> Values { get; }
+ /// <summary>
+ /// IComparable implementation for sorting the output order of the response
+ /// Default implementation is unsorted
+ /// </summary>
+ /// <param name="obj">Comparison object for sorting</param>
+ /// <returns></returns>
+ public virtual int CompareTo(object obj)
+ {
+ return 0;
+ }
This will fix the thrown exception and return a usable response.
However, it doesn't move any closer to permitting user-defined sorting like: /odata/Donations?$apply=groupby((email), aggregate(amount with sum as Total))&orderby=Total - if this is already on the roadmap or something I don't want to duplicate work.
xuzhg
kosinsky
The query: /odata/Donations?$apply=groupby((email), aggregate(amount with sum as Total))
Will throw an ArgumentException "(Failed to compare two elements in the array.)" -> "At least one object must implement IComparable."
The output result type of the $apply is an
IEnumerable<GroupByWrapper>, and apparently the serializer really needs to sort this before returning the result (even though I don't care and intentionally didn't specify a sort order). The default Compare function is used...FWIW, specifying an orderby doesn't solve the issue (the sort operation is being applied to GroupByWrappers, not the output EdmType).
/odata/Donations?$apply=groupby((email), aggregate(amount%20with%20sum%20as%20Total))&$orderby=Total
Assemblies affected
PackageReference Include="Microsoft.AspNetCore.OData" Version="7.1.0"
Reproduce steps
IEnumerable<GroupByWrapper>(also any other kind ofDynamicTypeWrapper) e.g. ?$apply=groupby((email), aggregate(amount with sum as Total))Expected result
Actual result
System.Collections.Comparer.cs throws: ArgumentException "(Failed to compare two elements in the array.)" -> "At least one object must implement IComparable."
Additional detail
Stacktrace for fun:
at System.Collections.Generic.GenericArraySortHelper1.Sort(T[] keys, Int32 index, Int32 length, IComparer1 comparer) in E:\A\_work\482\s\src\mscorlib\src\System\Collections\Generic\ArraySortHelper.cs:line 399 at System.Array.Sort[T](T[] array, Int32 index, Int32 length, IComparer1 comparer) in E:\A_work\482\s\src\mscorlib\src\System\Array.cs:line 1815 at System.Linq.EnumerableSorter1.Sort(TElement[] elements, Int32 count) in E:\A\_work\115\s\corefx\src\System.Linq\src\System\Linq\OrderedEnumerable.cs:line 512 at System.Linq.OrderedEnumerable1.2.Create[TSource](IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer1 comparer) in E:\A\_work\115\s\corefx\src\System.Linq\src\System\Linq\Lookup.cs:line 80 at System.Linq.GroupedEnumerable3.ToArray() in E:\A_work\115\s\corefx\src\System.Linq\src\System\Linq\Grouping.cs:line 227 at System.Linq.Buffer1..ctor(IEnumerable1 source) in E:\A_work\115\s\corefx\src\System.Linq\src\System\Linq\Buffer.cs:line 33 at System.Linq.OrderedEnumerable`1.2.MoveNext() in E:\A\_work\115\s\corefx\src\System.Linq\src\System\Linq\Select.cs:line 639 at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.ExceptionInterceptor1.EnumeratorExceptionInterceptor.MoveNext() in //src/EFCore/Query/Internal/LinqOperatorProvider.cs:line 143 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IEnumerable values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty) in //Src/Newtonsoft.Json/Serialization/JsonSerializerInternalWriter.cs:line 677 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType) in //Src/Newtonsoft.Json/Serialization/JsonSerializerInternalWriter.cs:line 80 at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType) in //Src/Newtonsoft.Json/JsonSerializer.cs:line 1151 at Microsoft.AspNetCore.Mvc.Formatters.JsonOutputFormatter.WriteObject(TextWriter writer, Object value) in /_/src/Microsoft.AspNetCore.Mvc.Formatters.Json/JsonOutputFormatter.cs:line 91 at Microsoft.AspNetCore.Mvc.Formatters.JsonOutputFormatter.