try another way to implement the data stucture

UserService.Test/UnitTest1.cs

@@ -1,34 +1,56 @@
 using NUnit.Framework;
+using System;
 using System.Threading.Tasks;
-using DataModels;
 using UserService.DatabaseLayer.Repositories;
+using UserService.Infrastructure.DataModels;
 
 namespace UserService.Test
 {
-    public class Tests
+    public class UserRepositoryTests
     {
-        [SetUp]
-        public void Setup()
-        {
-        }
-
         [Test]
+        [Order(2)]
         public async Task Test1()
         {
             var usersRepository = new UsersRepository();
-            var users = await usersRepository.GetAllAsync();
+            var users = await usersRepository.GetAllAsync().ConfigureAwait(false);
             Assert.AreEqual(users.Count, 1);
         }
 
         [Test]
+        [Order(1)]
         public async Task Test2()
         {
             var usersRepository = new UsersRepository();
             var user = new User
             {
-                FirstName = "Holger", LastName = "B<EFBFBD>rchers", IsActive = true
+                CommonName = "holger",
+                FirstName = "Holger",
+                LastName = "B<>rchers",
+                IsActive = true
             };
-            await usersRepository.AddAsync(user);
+            await usersRepository.AddAsync(user).ConfigureAwait(false);
+        }
+
+        [Test]
+        [Order(3)]
+        public async Task Test3()
+        {
+            var usersRepository = new UsersRepository();
+
+            var user = await usersRepository.GetAsync(x => x.CommonName == "holger").ConfigureAwait(false);
+            user.Description = DateTime.Now.ToString("O");
+            await usersRepository.UpdateAsync(user).ConfigureAwait(false);
+        }
+
+        [Test]
+        [Order(4)]
+        public async Task Test4()
+        {
+            var usersRepository = new UsersRepository();
+
+            var user = await usersRepository.GetAsync(x => x.CommonName == "holger").ConfigureAwait(false);
+            await usersRepository.DeleteAsync(user).ConfigureAwait(false);
         }
     }
 }