Update Sqlite demo

Src/Asp.Net/SqliteTest/UserTestCases/Models/Tree.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OrmTest
+{
+    public class Tree
+    {
+        [SqlSugar.SugarColumn(IsPrimaryKey =true)]
+        public int Id { get; set; }
+        public string Name { get; set; }
+        public int ParentId { get; set; }
+        [SqlSugar.SugarColumn(IsIgnore = true)]
+        public Tree Parent { get; set; }
+        [SqlSugar.SugarColumn(IsIgnore = true)]
+        public List<Tree> Child { get; set; }
+    }
+}