Update mapper

Src/Asp.Net/SqlServerTest/SqlServerTest.csproj

@@ -102,6 +102,7 @@
     <Compile Include="UnitTest\UCustom01.cs" />
     <Compile Include="UnitTest\UCustom02.cs" />
     <Compile Include="UnitTest\UCustom03.cs" />
+    <Compile Include="UnitTest\UCustom08.cs" />
     <Compile Include="UnitTest\UCustom07.cs" />
     <Compile Include="UnitTest\UCustom06.cs" />
     <Compile Include="UnitTest\UCustom05.cs" />

Src/Asp.Net/SqlServerTest/UnitTest/Main.cs

@@ -31,6 +31,7 @@ namespace OrmTest
         }
         public static void Init()
         {
+            UCustom08.Init();
             UCustom07.Init();
             UCustom01.Init();
             UCustom02.Init();

Src/Asp.Net/SqlServerTest/UnitTest/UCustom08.cs

@@ -0,0 +1,47 @@
+using OrmTest.UnitTest.Models;
+using SqlSugar;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OrmTest
+{
+    public class UCustom08
+    {
+        public static void Init()
+        {
+            var db = NewUnitTest.Db;
+            db.CodeFirst.InitTables<Unitasfa1>();
+            db.CodeFirst.InitTables<Unitasfa1Item>();
+         db.Queryable<Unitasfa1>().Where(new List<IConditionalModel>
+            {
+                new ConditionalModel(){
+                 ConditionalType=ConditionalType.In,
+                   FieldName="id",
+                   FieldValue="null"
+                }
+            }).ToList();
+            db.Insertable(new Unitasfa1() { Id = Guid.NewGuid() }).ExecuteCommand();
+            db.Insertable(new Unitasfa1() { Id = Guid.NewGuid(),ItemId=Guid.NewGuid() }).ExecuteCommand();
+            var list = db.Queryable<Unitasfa1>().Mapper(x => x.items, x => x.ItemId).ToList();
+        }
+        public class Unitasfa1
+        {
+            [SugarColumn(IsPrimaryKey = true)]
+            public Guid Id { get; set; }
+            [SugarColumn(IsNullable = true)]
+            public Guid? ItemId { get; set; }
+
+            [SugarColumn(IsIgnore = true)]
+            public List<Unitasfa1Item> items { get; set; }
+        }
+
+        public class Unitasfa1Item
+        {
+            [SugarColumn(IsPrimaryKey = true)]
+            public Guid Id { get; set; }
+        }
+    }
+}

Src/Asp.Net/SqlSugar/Abstract/QueryableProvider/QueryableProvider.cs

@@ -2173,6 +2173,10 @@ namespace SqlSugar
                         Check.Exception(true, ".Mapper() parameter error");
                     }
                     List<string> inValues = entitys.Select(it => it.GetType().GetProperty(filedName).GetValue(it, null).ObjToString()).ToList();
+                    if (inValues!=null&& inValues.Any()&&UtilMethods.GetUnderType(entitys.First().GetType().GetProperty(filedName).PropertyType) == UtilConstants.GuidType) 
+                    {
+                        inValues = inValues.Select(x => x == "" ? "null" : x).Distinct().ToList();
+                    }
                     List<IConditionalModel> wheres = new List<IConditionalModel>()
                     {
                        new ConditionalModel()