From 0b525ce9f51cb8cebdb49d1759d6abbb2f39f60b Mon Sep 17 00:00:00 2001
From: alex-310 <142961121+alex-310@users.noreply.github.com>
Date: Wed, 23 Aug 2023 13:12:51 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D=E5=AD=97=E6=AE=B5null?=
 =?UTF-8?q?=E6=97=B6order=20by=E9=94=99=E8=AF=AF?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../StreamMergeAsync/OrderStreamMergeAsyncEnumerator.cs     | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/ShardingCore/Sharding/Enumerators/StreamMergeAsync/OrderStreamMergeAsyncEnumerator.cs b/src/ShardingCore/Sharding/Enumerators/StreamMergeAsync/OrderStreamMergeAsyncEnumerator.cs
index cf1f9d55..a484793c 100644
--- a/src/ShardingCore/Sharding/Enumerators/StreamMergeAsync/OrderStreamMergeAsyncEnumerator.cs
+++ b/src/ShardingCore/Sharding/Enumerators/StreamMergeAsync/OrderStreamMergeAsyncEnumerator.cs
@@ -106,6 +106,10 @@ namespace ShardingCore.Sharding.Enumerators
                 {
                     list.Add((IComparable)value);
                 }
+                else if (value == null) // Support Nullable<xx>
+                {
+                    list.Add(null);
+                }
                 else
                 {
                     throw new NotSupportedException($"order by value [{order}] must  implements IComparable");  
@@ -142,4 +146,4 @@ namespace ShardingCore.Sharding.Enumerators
 #endif
 
     }
-}
\ No newline at end of file
+}