Add unit test

Src/Asp.Net/PgSqlTest/PgSqlTest.csproj

@@ -107,6 +107,7 @@
     <Compile Include="UnitTest\UCustom012.cs" />
     <Compile Include="UnitTest\UCustom014.cs" />
     <Compile Include="UnitTest\UCustom015.cs" />
+    <Compile Include="UnitTest\UCustom016.cs" />
     <Compile Include="UnitTest\USave.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />

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

@@ -31,6 +31,7 @@ namespace OrmTest
         }
         public static void Init()
         {
+            UCustom016.Init();
             UCustom08.Init();
             UCustom012.Init();
             UCustom014.Init();

Src/Asp.Net/PgSqlTest/UnitTest/UCustom016.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SqlSugar;
+namespace OrmTest
+{
+ 
+    public class UCustom016
+    {
+        public static void Init() 
+        {
+            var db = NewUnitTest.Db;
+            var list0 = new TestEntity
+            {
+                Id = 1,
+                Data1 = null,
+                Data2 = null
+            };
+            var list1 = new List<TestEntity>
+                {
+                    new TestEntity
+                    {
+                        Id = 2,
+                        Data1 = null,
+                        Data2 = null
+                    },
+                };
+            var list2 = new List<TestEntity>
+            {
+                new TestEntity
+                {
+                    Id = 3,
+                    Data1 = null,
+                    Data2 = null
+                },
+                new TestEntity
+                {
+                    Id = 4,
+                    Data1 = null,
+                    Data2 = null
+                },
+            };
+            db.CodeFirst.InitTables<TestEntity>();
+            db.DbMaintenance.TruncateTable<TestEntity>();
+            db.Insertable(list0).ExecuteCommand();
+            db.Insertable(list1).ExecuteCommand ();
+            db.Insertable(list2).ExecuteCommand();
+            var list3 = db.Queryable<TestEntity>().ToList();
+            if (list3.First().Data1 != null) 
+            {
+                throw new Exception("unit error");
+            }
+        }
+        public enum TestEnum
+        {
+            A = 1,
+            B = 2,
+            C = 3,
+            D = 4,
+        }
+        [SugarTable("UnitNullenum1")]
+        public class TestEntity
+        {
+            [SugarColumn(IsPrimaryKey = true)]
+            public long Id { get; set; }
+            [SugarColumn(IsNullable =true)]
+            public TestEnum? Data1 { get; set; }
+            [SugarColumn(IsNullable = true)]
+            public int? Data2 { get; set; }
+        }
+    }
+}