Update demo

Src/Asp.NetCore2/SqlSeverTest/SqliteTest/UnitTest/UCodeFirst.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OrmTest
+{
+    public partial class NewUnitTest
+    {
+        public static void CodeFirst()
+        {
+            if (Db.DbMaintenance.IsAnyTable("UnitCodeTest1", false))
+                Db.DbMaintenance.DropTable("UnitCodeTest1");
+            Db.CodeFirst.InitTables<UnitCodeTest1>();
+        }
+        public class UnitCodeTest1
+        {
+            public int Id { get; set; }
+            public DateTime? CreateDate { get; set; }
+        }
+    }
+}