diff --git a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/IMemoryDatabase.cs b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/IMemoryDatabase.cs
index 3b9ca358bf..7cbaf15e70 100644
--- a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/IMemoryDatabase.cs
+++ b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/IMemoryDatabase.cs
@@ -5,5 +5,7 @@ namespace Volo.Abp.Domain.Repositories.MemoryDb
     public interface IMemoryDatabase
     {
         List<TEntity> Collection<TEntity>();
+
+        TPrimaryKey GenerateNextId<TEntity, TPrimaryKey>();
     }
 }
\ No newline at end of file
diff --git a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/InMemoryIdGenerator.cs b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/InMemoryIdGenerator.cs
new file mode 100644
index 0000000000..1741d2cc02
--- /dev/null
+++ b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/InMemoryIdGenerator.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Threading;
+
+namespace Volo.Abp.Domain.Repositories.MemoryDb
+{
+    internal class InMemoryIdGenerator
+    {
+        private int _lastInt;
+        private long _lastLong;
+
+        public TPrimaryKey GenerateNext<TPrimaryKey>()
+        {
+            if (typeof(TPrimaryKey) == typeof(Guid))
+            {
+                return (TPrimaryKey)(object)Guid.NewGuid();
+            }
+
+            if (typeof(TPrimaryKey) == typeof(int))
+            {
+                return (TPrimaryKey)(object)Interlocked.Increment(ref _lastInt);
+            }
+
+            if (typeof(TPrimaryKey) == typeof(long))
+            {
+                return (TPrimaryKey)(object)Interlocked.Increment(ref _lastLong);
+            }
+
+            throw new AbpException("Not supported PrimaryKey type: " + typeof(TPrimaryKey).FullName);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDatabase.cs b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDatabase.cs
index dc6c6ffc99..332138eae2 100644
--- a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDatabase.cs
+++ b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDatabase.cs
@@ -8,16 +8,24 @@ namespace Volo.Abp.Domain.Repositories.MemoryDb
     {
         private readonly ConcurrentDictionary<Type, object> _sets;
 
-        private readonly object _syncObj = new object();
+        private readonly ConcurrentDictionary<Type, InMemoryIdGenerator> _idGenerators;
 
         public MemoryDatabase()
         {
             _sets = new ConcurrentDictionary<Type, object>();
+            _idGenerators = new ConcurrentDictionary<Type, InMemoryIdGenerator>();
         }
 
         public List<TEntity> Collection<TEntity>()
         {
             return _sets.GetOrAdd(typeof(TEntity), _ => new List<TEntity>()) as List<TEntity>;
         }
+
+        public TPrimaryKey GenerateNextId<TEntity, TPrimaryKey>()
+        {
+            return _idGenerators
+                .GetOrAdd(typeof(TEntity), () => new InMemoryIdGenerator())
+                .GenerateNext<TPrimaryKey>();
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDbRepository.cs b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDbRepository.cs
index 78075b6752..93be92bd09 100644
--- a/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDbRepository.cs
+++ b/src/Volo.Abp.MemoryDb/Volo/Abp/Domain/Repositories/MemoryDb/MemoryDbRepository.cs
@@ -33,10 +33,22 @@ namespace Volo.Abp.Domain.Repositories.MemoryDb
 
         public override TEntity Insert(TEntity entity, bool autoSave = false)
         {
+            SetIdIfNeeded(entity);
             Collection.Add(entity);
             return entity;
         }
 
+        private void SetIdIfNeeded(TEntity entity)
+        {
+            if (typeof(TPrimaryKey) == typeof(int) || typeof(TPrimaryKey) == typeof(long) || typeof(TPrimaryKey) == typeof(Guid))
+            {
+                if (entity.IsTransient())
+                {
+                    entity.Id = Database.GenerateNextId<TEntity, TPrimaryKey>();
+                }
+            }
+        }
+
         public override TEntity Update(TEntity entity)
         {
             return entity;
diff --git a/test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/Mvc/PersonAppService_Tests.cs b/test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/Mvc/PersonAppService_Tests.cs
index 5684bfbb9f..9174e912c5 100644
--- a/test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/Mvc/PersonAppService_Tests.cs
+++ b/test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/Mvc/PersonAppService_Tests.cs
@@ -153,5 +153,28 @@ namespace Volo.Abp.AspNetCore.Mvc
             personInDb.ShouldNotBeNull();
             personInDb.Phones.Any(p => p.Number == phoneNumberToAdd).ShouldBeTrue();
         }
+
+        [Fact]
+        public async Task GetPhones_Test()
+        {
+            var douglas = _personRepository.GetList().First(p => p.Name == "Douglas");
+
+            //Ideally should be [GET] /api/person/{id}/phones?type=office
+            var result = await GetResponseAsObjectAsync<ListResultDto<PhoneDto>>("/api/services/app/person/GetPhones?id=" + douglas.Id);
+            result.Items.Count.ShouldBe(douglas.Phones.Count);
+        }
+
+        [Fact]
+        public async Task DeletePhone_Test()
+        {
+            var douglas = _personRepository.GetList().First(p => p.Name == "Douglas");
+            var firstPhone = douglas.Phones.First();
+
+            //Ideally should be [DELETE] /api/app/person/{id}
+            await Client.DeleteAsync("/api/services/app/person/DeletePhone?id=" + douglas.Id + "&phoneId=" + firstPhone.Id);
+
+            douglas = _personRepository.GetList().First(p => p.Name == "Douglas");
+            douglas.Phones.Any(p => p.Id == firstPhone.Id).ShouldBeFalse();
+        }
     }
 }
diff --git a/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/IPersonAppService.cs b/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/IPersonAppService.cs
index 6a44aa4d73..2643bcab6f 100644
--- a/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/IPersonAppService.cs
+++ b/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/IPersonAppService.cs
@@ -7,7 +7,6 @@ namespace Volo.Abp.TestApp.Application
 {
     public interface IPersonAppService : IAsyncCrudAppService<PersonDto>
     {
-        //URL: [GET] /api/people/{id}?type=office
         Task<ListResultDto<PhoneDto>> GetPhones(Guid id, GetPersonPhonesFilter filter);
 
         Task<PhoneDto> AddPhone(Guid id, PhoneDto phoneDto);
diff --git a/test/Volo.Abp.TestApp/Volo/Abp/TestApp/TestDataBuilder.cs b/test/Volo.Abp.TestApp/Volo/Abp/TestApp/TestDataBuilder.cs
index d5b7eb8c3f..4bfec673bf 100644
--- a/test/Volo.Abp.TestApp/Volo/Abp/TestApp/TestDataBuilder.cs
+++ b/test/Volo.Abp.TestApp/Volo/Abp/TestApp/TestDataBuilder.cs
@@ -16,7 +16,15 @@ namespace Volo.Abp.TestApp
 
         public void Build()
         {
-            _personRepository.Insert(new Person(Guid.NewGuid(), "Douglas", 42));
+            AddPeople();
+        }
+
+        private void AddPeople()
+        {
+            var douglas = new Person(Guid.NewGuid(), "Douglas", 42);
+            douglas.Phones.Add(new Phone(douglas.Id, "123456789"));
+            douglas.Phones.Add(new Phone(douglas.Id, "123456780", PhoneType.Home));
+            _personRepository.Insert(douglas);
         }
     }
 }
\ No newline at end of file