This is the third post in the series.  You can see the other to posts here:

• Creating a Web Application Using MVC, Unity and NHibernate – Part 1, Setting up Nhibernate
• Creating a Web Application Using MVC, Unity and NHibernate – Part 2, Simple Querying using Nhibernate

The Service Layer

Now that I have a data layer, I would like to create a service layer that takes the records retrieved from the database and then applies the business rules to them.  Some of these rules are that I would like to apply are:

• I would only like to show the first 5 most recent posts on the home page.
• I would like catch any exceptions and log them.

If I was not testing this function first, my code would look something like this.

   37         public List<NewsItemDto> GetLatestNewsItems(int numberOfItems)

   38         {

   39             List<NewsItemDto> items;

   40 

   41             try

   42             {

   43                 using (ISessionFactory sessionFactory = (new Configuration().Configure().BuildSessionFactory()))

   44                 {

   45 

   46                     using (ISession session = new object() as ISession)

   47                     {

   48                         var provider = new NHibernateDataProvider(session);

   49                         var result = provider.GetAllPublishedFrontPagePosts();

   50                         items = result != null ? result.OrderByDescending(i => i.DatePublished).Take(5).ToList() : null;

   51                     }

   52                 }

   53             }

   54             catch (Exception ex)

   55             {

   56                 ExceptionPolicy.HandleException(ex, "General");

   57                 throw;

   58             }

   59 

   60             return items;

   61 

   62         }

Here are some of the issues with this method.

• The method is depending on the NHibernateDataProvider class.  This means I have to have a database setup for this test.  If I have a lot of service layer tests connecting to the database then these tests are going to take forever to run.
• Another issue with being dependant on the NHibernateDataProvider class is now I have to some way to create an ISessionFactory class.
• For logging errors, I have a dependency on using Microsoft Exception Handler class so if I ever want to change that logging plumbing I have to change it all over my app.

·          In general there is a lot of stuff happening but really all I want to test is getting a list of news items that match the count I want and are sorted in the correct order.

The Test

Okay, so back to the drawing board.  Let me start with the test first and see if I can test this function without having it connect to a database. To do this I am going extract the interface for the NHibernateDataProvider class and call it IDataProvider.

    7     public interface IDataProvider

    8     {

    9         IQueryable<NewsItemDto> GetAllPublishedFrontPagePosts();

   10         NewsItemDto GetNewsItemByItemId(long newsItemId);

   11         IList<AuthorDto> GetAuthorsBy(string userId);

   12     }

In this example, I am using the Microsoft Enterprise Library Exception Policy class for logging exceptions.  This class is sealed with one static method class called HandleException.  Because of this, I cannot extract an interface, so for now I am going wrap this class in another concrete class that implements an interface that I can inject.

The interface looks like this:

    5     public interface ILogger

    6     {

    7         void LogException(Exception ex);

    8     }

The derived concrete class looks like this:

    6     public class MicrosoftLogger : ILogger

    7     {

    8         public void LogException(Exception ex)

    9         {

   10             ExceptionPolicy.HandleException(ex, "General");

   11         }

   12     }

Now I can mock my data provider and my logging class in my test, and I can also inject these classes into my web application later on.

So now the constructor of my service class looks like this:

   12     public class NewsItemService : INewsItemService

   13     {

   14         private readonly IDataProvider newsDataProvider;

   15         private readonly ILogger logger;

   16 

   17         public NewsItemService(IDataProvider newsDataProvider, ILogger logger)

   18         {

   19             this.newsDataProvider = newsDataProvider;

   20             this.logger = logger;

   21         }

So I mentioned that I am going mock the data provider class and to do this I am going use my mock tool of choice Rhino.Mocks.

   74         [TestMethod()]

   75         public void NewsItemService_get_latest_news_items_should_return_5_most_recent()

   76         {

   77             var mockRepository = new MockRepository();

   78             var dataProvider = mockRepository.StrictMock<IDataProvider>();

   79             var mockLogger = mockRepository.StrictMock<ILogger>();

   80 

   81             using (mockRepository.Record())

   82             {

   83                 Expect.Call(dataProvider.GetAllPublishedFrontPagePosts()).Return(PostRepository.GetNewsItems());

   84             }

   85 

   86             var numberOfItems = 5;

   87             var expected = 5;

   88             using (mockRepository.Playback())

   89             {

   90                 var target = new NewsItemService(dataProvider, mockLogger);

   91                 var items = target.GetLatestNewsItems(numberOfItems);

   92                 var currentDate = DateTime.MaxValue;

   93 

   94                 foreach (var item in items)

   95                 {

   96                     Assert.IsTrue(currentDate > item.DatePublished, currentDate.ToShortDateString() + " is not > " + item.DatePublished.ToShortDateString());

   97                     currentDate = item.DatePublished;

   98                 }

   99 

  100                 Assert.AreEqual(items.Count, expected, "Get the latest news does not eaqual 5");

  101             }

  102 

  103         }

In the test above instead of connecting to the database, I first tell Rhino Mocks to mock my data provider.  I pass it the IDataProvider interface and Rhino Mocks gives me back an instantiated data provider even though there is now derived concrete class involved.  I then do the same for the logging object.

In the Record section, I am telling Rhino Mocks that later on when I actually test my service object to expect it to make a call to the data provider class with a specific set of parameters (in this case I have no parameters) and when this occurs return my mocked result.  Once I have recorded all my expected calls that I want to mock, I can then proceed to the Playback method to test my service.

Inside the Playback I write my test as if I was actually connecting to a database and I assert that I got back 5 records sorted by the published date.

So I test and my test fails because I have not implemented the GetLatestNewsItems yet so let me do that.

   23         public List<NewsItemDto> GetLatestNewsItems(int numberOfItems)

   24         {

   25             try

   26             {

   27                 var items = newsDataProvider.GetAllPublishedFrontPagePosts();

   28                 return items != null ? items.OrderByDescending(i => i.DatePublished).Take(5).ToList() : null;

   29             }

   30             catch(Exception ex  )

   31             {

   32                 logger.LogException(ex);

   33                 throw;

   34             }

   35         }

Now I can test my object without being dependant on any concrete classes, and I can also inject my dependencies later on using Unity.

Introduction

In the last post I set up NHibernate and created a simple test to retrieve one record from the database.  Now I would like to join the News table and Author table together and then create a test to see if I can successfully retrieve a record that contains both data from both tables joined together.

If you recall my schema looks like this:

So the first thing I would like to do is change create the mapping and DTO class for the Author table, but before I can do that, I need to add a reference of the Iesi.Collections.dll external assembly to my projects so I can create the ISet<> collection object.  Since one author can have many news items, my author class will have a collection of news items.  Since each of these news items must be unique, the ISet collection object will not allow you to add duplicate news items.

The Author Mapping File and Class

The Author mapping file will be set up just like the News mapping file:

    1 <?xml version="1.0" encoding="utf-8" ?>

    2 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="News.Core" namespace="News.Core.Dto">

    3   <class name="News.Core.Dto.AuthorDto, News.Core" table="Author">

    4     <id column="AuthorId" name="AuthorId" type="long" unsaved-value="0">

    5       <generator class="native"></generator>

    6     </id>

    7     <property column="UserName" name="UserName" type="string" not-null="true"/>

    8     <property column="FirstName" name="FirstName" type="string" not-null="true"/>

    9     <property column="LastName" name="LastName" type="string" not-null="true"/>

   10     <property column="Password" name="Password" type="string" not-null="true"/>

   11     <property column="EmailAddress" name="EmailAddress" type="string" not-null="true"/>

   12     <property column="DateAdded" name ="DateAdded" type="DateTime" not-null="true" />

   13     <property column="DateUpdated" name ="DateUpdated" type="DateTime" not-null="true" />

   14     <property column="IsActive" name="IsActive" />

   15 

   16     <set name="NewsItems" table="News" generic="true" inverse="true">

   17       <key column="AuthorId" />

   18       <one-to-many class="News.Core.Dto.NewsItemDto, News.Core"/>

   19     </set>

   20   </class>

   21 </hibernate-mapping>

The first thing I need to is add the hibernate-mapping tag with xmlns namespace set so I can get the intellisense.  Next I add the Author class, specifying its namespace and assembly location, and just like the NewsItem class I start mapping the fields to the class properties.

As seen from the schema shown above, the Author table has a foreign key relationship in the News table, so I need to tell NHibernate about that relationship.  So to map the relationship, I have added a “set” tag.  The set tag tells NHibernate that the Author class has a collection of NewsItems and each of these news items are unique.  Now, if I wanted the Author class to have a collection of NewsItems that were not unique then I would use the bag tag, but in my case the set tag is what I want.

Here’s what’s going on:

·          The set attribute name is the child class that will be contained in the Author class.

·          The table attribute specifies the child table in the database that has the foreign key relationship.  In my case it is the News table.

·          Generic tells NHibernate that I want to use the ISet<T> collection  (Note:  This is a class that NHibernate provides is like the IList<T> class, but this class will not let you add a duplicate item to its collection.  I need to add a reference to the Iesi.Collections.dll assembly to use it.

·          Inverse tells NHibernate that I want the child class to control the relationship and not the parent.

·          The key column tells NHibernate what the foreign key field is in the child table.

·          And finally the one-to-many tag tells NHibernate what namespace and assembly the child class is in.

Woops!  Don't forget to make the mapping xml file an embedded resource.

Here is the class file.

    6     public class AuthorDto

    7     {

    8 

    9         public virtual long AuthorId { get; set; }

   10 

   11         public virtual string UserName { get; set; }

   12 

   13         public virtual string FirstName { get; set; }

   14 

   15         public virtual string LastName { get; set; }

   16 

   17         public virtual string Password { get; set; }

   18 

   19         public virtual string EmailAddress { get; set; }

   20 

   21         public virtual DateTime DateAdded { get; set;  }

   22 

   23         public virtual DateTime DateUpdated { get; set; }

   24 

   25         public virtual bool IsActive { get; set; }

   26 

   27         public virtual ISet<NewsItemDto> NewsItems { get; set; }

   28 

   29     }

Notice the ISet class?  Cool!

The News Mapping File and Class

The News class will slightly change.  Instead of holding the AuthorId field, the News class will be holding its parent Author class, so I will need to change the mapping file to reflect this also.

So here is the mapping file:

    1 <?xml version="1.0" encoding="utf-8" ?>

    2 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Audubon.Core" namespace="Audubon.Core.Dto">

    3   <class name="Audubon.Core.Dto.NewsItemDto, Audubon.Core" table="News">

    4     <id column="NewsId" name="NewsId" type="long" unsaved-value="0">

    5       <generator class="native"></generator>

    6     </id>

    7     <many-to-one name="Author" column="AuthorId" not-null="true" class="Audubon.Core.Dto.AuthorDto, Audubon.Core" />

    8     <property column="DateAdded" name="DateAdded" type="DateTime" not-null="true"/>

    9     <property column="DateUpdated" name="DateUpdated" type="DateTime" not-null="true"/>

   10     <property column="DatePublished" name ="DatePublished" type="DateTime" not-null="true" />

   11     <property column="Title" name="Title" type="string" not-null="true"/>

   12     <property column="ShortDescription" name="ShortDescription" type="string" not-null="false"/>

   13     <property column="Body" name="Body" type="string" not-null="true"/>

   14     <property column="IsFrontPage" name="IsFrontPage"/>

   15     <property column="IsPublished" name="IsPublished"/>

   16 

   17   </class>

   18 </hibernate-mapping>

Notice I have changed the AuthorId property tag to a many-to-one tag which specified the Author class.

Here is the NewsItem class with the modification for Author property:

    5     public class NewsItemDto

    6     {

    7         public virtual long NewsId { get; set; }

    8 

    9         public virtual AuthorDto Author { get; set; }

   10 

   11         public virtual DateTime DateAdded { get; set; }

   12 

   13         public virtual DateTime DatePublished { get; set; }

   14 

   15         public virtual DateTime DateUpdated { get; set; }

   16 

   17         public virtual string Title { get; set; }

   18 

   19         public virtual string ShortDescription { get; set; }

   20 

   21         public virtual string Body { get; set; }

   22 

   23         public virtual bool IsFrontPage { get; set; }

   24 

   25         public virtual bool IsPublished { get; set; }

   26     }

The Test

Now before I get into the test, at this point I should probably acquaint myself with the idea of lazy loading verses eager loading.  If you look at the two class above, the Author class has a collection of NewsItems classes and each of the NewsItem classes has a Author class which has a collection NewsItem classes, etc, etc, etc…

To get around this circular mapping, NHibernate uses the Proxy Pattern so that NewsItem class is not actually loaded until asked for in the code.  I can either get all the collection classes up front (eager loading) or I can get the class when I need them (lazy loading).  David Hayden wrote a nice explanation about the ramifications of either one using LightSpeed that you can read here.

I state that now, because I want to test that if I search for an author using a user id that I will get a collection of news items back for that author.  So since I am using lazy loading, I am not actually going to make to database calls for the news items until I inspect the collection of news items in the authors object I get back.

So here is the test:

  104         [TestMethod]

  105         public void NHibernateCanGetNewsItemsBySpecifiedUserId()

  106         {

  107             const string userId = "testuser";

  108             var target = new NHibernateDataProvider(session);

  109             var authors = target.GetAuthorsBy(userId);

  110 

  111             Assert.IsTrue(authors.Count > 0, "Authors count is not greater than 0");

  112             Assert.IsTrue(authors[0].NewsItems.Count >0, "Author's news items count is not greater than 0");

  113             Assert.IsFalse(authors.Count > 1, "Retrieved too many authors");

I am testing that my function GetAuthorsBy will return a collection of NewsItems.

Here is the function:

   42         public IList<AuthorDto> GetAuthorsBy(string userId)

   43         {

   44             return _session.CreateCriteria(typeof(AuthorDto))

   45                 .Add(Restrictions.Eq("UserName", userId))

   46                 .SetResultTransformer(new DistinctRootEntityResultTransformer())

   47                 .List<AuthorDto>();

   48 

   49         }

This function is using the NHibernate API to query the Author table by passing the userid.

Here is what is happening here:

·          CreateCritera starts off by asking what class I want to return.  I am telling to return a collection of Authors.

·          To add the Where Clause, I use the Add extension function and pass in the Restrictions.Eq function passing the property name and matching value.

·          By default, it is possible for me to get author “A” and then get author “B” and then again get author “A” in the collection, each with their own set of news items.  To avoid this I want to combine all duplicates so they only show up once.  Essentially this would be the equivalent to the DISTINCT statement in SQL.  I can do this using the SetResultTransformer extension function passing in the DistinctRootEntityResultTransformer.  This function will take the collection and merge the duplicates together (this done in memory not in the database).  Ayende gives some other examples and explanations here.

·          Finally the List extension tells NHibernate that I want a strongly types IList<AuthorDTO> class.

So when the function is called the following query is made to the database.

NHibernate: SELECT this_.AuthorId as AuthorId1_0_, this_.UserName as UserName1_0_, this_.FirstName as FirstName1_0_, this_.LastName as LastName1_0_, this_.Password as Password1_0_, this_.EmailAddress as EmailAdd6_1_0_, this_.DateAdded as DateAdded1_0_, this_.DateUpdated as DateUpda8_1_0_, this_.IsActive as IsActive1_0_ FROM Author this_ WHERE this_.UserName = @p0; @p0 = 'testuser'

Then when the test does an assert on the NewsItem count the following query is made.

NHibernate: SELECT newsitems0_.AuthorId as AuthorId1_, newsitems0_.NewsId as NewsId1_, newsitems0_.NewsId as NewsId0_0_, newsitems0_.AuthorId as AuthorId0_0_, newsitems0_.DateAdded as DateAdded0_0_, newsitems0_.DateUpdated as DateUpda4_0_0_, newsitems0_.DatePublished as DatePubl5_0_0_, newsitems0_.Title as Title0_0_, newsitems0_.ShortDescription as ShortDes7_0_0_, newsitems0_.Body as Body0_0_, newsitems0_.IsFrontPage as IsFrontP9_0_0_, newsitems0_.IsPublished as IsPubli10_0_0_ FROM News newsitems0_ WHERE newsitems0_.AuthorId=@p0; @p0 = '1'

In the next post I will look at testing the Service layer using Rhino Mocks and possibly throw in my first example of how I am going to use Unity.

Introduction

I thought it would be useful to document what it would take to incorporate building a web application that is designed with the Microsoft MVC framework, that also incorporated using NHibernate as a O/R Mapper and uses Microsoft Unity as the Dependency Injection, IoC framework.  I must confess, I am not an expert of any of these tools, so I welcome feedback from the community.  The reason I am doing this to begin with, is there is not a whole a lot of documentation on of this “stuff” by themselves let alone all together, so I am hoping fill a little bit of that void.  If you think there are better approaches then what I am doing, feel free to provide feedback.   I am basically doing this for my own enrichment and if it is also helpful to the community, then—well—even better.

Since this going to have to be a series of posts, I will probably not cover every aspect of this application all at once, so if what you are looking for is not in this post, then be patient and maybe I will get to it in a later one.  As a matter of fact, since I am going to be adhering to a test first approach (red, green, refactor), I will probably not get to the MVC framework until several posts from now.  The first few posts will only be covering tests.

Setting up NHibernate

I have mentioned this before, but if you are new to NHibernate and don’t know how to get started, I highly recommend the Summer of NHibernate videos by Stephen Bohlen.  The download of NHibernate is located here.  Once downloaded, the first thing I need to do is put the NHibernate schema files in the Visual Studio schema folder (my folder is located here C:\Program Files\Microsoft Visual Studio 9.0\Xml\Schemas) so I can get intellisense on the configuration and mapping files. 

In general, for all the external libraries, it is useful to place them all in a folder location relative to, or just inside your solution so, for example, if you are using source control the other developer machines will pick up the references without any problems.  Thus, I am doing the same with this application, and will then be referencing the NHibernate.dll in all my relevant projects.  In my case, I am only going to have a Web, Core, and Test project so I will reference it for now in the Core and Test project.  I will probably need to reference in the web project once I set up Unity, but I will leave it out for now.

The next thing I will need to do is to create a NHibernate configuration file.  One of the cool concepts NHibernate follows is the Convention over Configuration paradigm.  That is, as long as I follow a certain convention, I will not need to configure certain aspects of NHibernate when setting it up.  So if I create a configuration file and name it hibernate.cfg.xml, then set is build action to copy to output folder, I will not need to tell NHibernate where the configuration file is.  Note:  I tried this in a Microsoft Team Test project and for some reason the test project would not copy that file to the output folder so I ended up having to configure the path anyway.

Here is the configuration file that is in the root directory of my test project.

    1 <?xml version="1.0" encoding="utf-8" ?>

    2 <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">

    3   <session-factory name="NHibernate.Test">

    4     <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>

    5     <property name="connection.connection_string">

    6       Data Source=(local);Initial Catalog=News;Persist Security Info=True;User ID=my_dev;Password=my_dev

    7     </property>

    8     <property name="adonet.batch_size">10</property>

    9     <property name="show_sql">true</property>

   10     <property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property>

   11     <property name="use_outer_join">true</property>

   12     <property name="command_timeout">444</property>

   13     <property name="query.substitutions">true 1, false 0, yes 'Y', no 'N'</property>

   14     <mapping assembly="News.Core"/>

   15   </session-factory>

   16 </hibernate-configuration>

Notice that in the root tag that since I place the NHibernate schema files in the Visual Studio schema folder I now have access to intellisense.  You can see the property setting definitions here, but here are the important nodes

·          The show_sql property is going to be useful when debugging so I can see the SQL statements.  I will turn this off in production because it is expensive.

·          The dialect is going to tell NHibernate to what specific database language and version it is going to translate the SQL to.

·          The mapping tells NHibernate where the mapping files and classes are located.

Once the configuration file is created, I then can call it from my code and create the ISessionFactory.  I will talk about my approach later in another post, but essentially because ISessionFactory is expensive to create and there also some threading concerns with creating it; I am going to create it differently in the test project than in the web project.  In both cases, I am going to implement an interface I created call ISessionFactoryManager.  This interface, as of now, will have one method called GetSessionFactory.  The code in my test project looks like this.

    1 using News.Core.Data;

    2 using NHibernate;

    3 using NHibernate.Cfg;

    4 

    5 namespace News.Web.Tests

    6 {

    7     internal class TestSessionFactoryManager : ISessionFactoryManager

    8     {

    9         public ISessionFactory GetSessionFactory()

   10         {

   11             string path = @"C:\Projects\News\Src\News.Web.Tests\hibernate.cfg.xml";

   12             var cfg = new Configuration();

   13             cfg.Configure(path);

   14             return cfg.BuildSessionFactory();

   15 

   16         }

   17     }

   18 }

 Note:  If I want, I can also add properties at run time.  For example, say my connection string is stored in a super secret place; I could get it and set the ISessionFactory with the following code.  It just has to be done before the BuildSessionFactory is called, because once called, it cannot be changed.

  15             cfg.Properties.Add("connection.connection_string",connectionString);

Once the BuildSessionFactory method is called, Nhibernate goes and retrieves the configuration file, and also the Mapping files (I will discuss later) and returns the session factory.  I now can open sessions to the database and do whatever database CRUD I need to do.

Mapping Tables to Classes

 For my example, I am going to have two tables with the following schema:

For this post, I am only going to worry about the News table.  Again, using convention over configuration, I have mapping file named NewsItemDto.hbm.xml so I do not have to tell NHibernate where it is.  I need to make sure this file is an embedded resource, so it can be referenced.  The content of the file looks like this:

    1 <?xml version="1.0" encoding="utf-8" ?>

    2 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="News.Core" namespace="News.Core.Dto">

    3   <class name="News.Core.Dto.NewsItemDto, News.Core" table="News">

    4     <id column="NewsId" name="NewsId" type="long" unsaved-value="0">

    5       <generator class="native"></generator>

    6     </id>

    7     <property column="AuthorId" name="AuthorId" type="long" not-null="true"/>

    8     <property column="DateAdded" name="DateAdded" type="DateTime" not-null="true"/>

    9     <property column="DateUpdated" name="DateUpdated" type="DateTime" not-null="true"/>

   10     <property column="DatePublished" name ="DatePublished" type="DateTime" not-null="true" />

   11     <property column="Title" name="Title" type="string" not-null="true"/>

   12     <property column="ShortDescription" name="ShortDescription" type="string" not-null="false"/>

   13     <property column="Body" name="Body" type="string" not-null="true"/>

   14     <property column="IsFrontPage" name="IsFrontPage"/>

   15     <property column="IsPublished" name="IsPublished"/>

   16   </class>

   17 </hibernate-mapping>

Again, the root references the NHibernate mapping schema which will give me intellisense.  You can see all the property settings here.  In the class, I tell it the namespace and assembly name where the class is located.  The ID identifies the primary key of the table.  By setting the generator attribute to native, I am telling NHibernate that the field is an identity field and the value is created by the database.

Here is the code for the class:

    5     public class NewsItemDto

    6     {

    7         public virtual long NewsId { get; set; }

    8 

    9         public virtual long AuthorId { get; set; }

   10 

   11         public virtual DateTime DateAdded { get; set; }

   12 

   13         public virtual DateTime DatePublished { get; set; }

   14 

   15         public virtual DateTime DateUpdated { get; set; }

   16 

   17         public virtual string Title { get; set; }

   18 

   19         public virtual string ShortDescription { get; set; }

   20 

   21         public virtual string Body { get; set; }

   22 

   23         public virtual bool IsFrontPage { get; set; }

   24 

   25         public virtual bool IsPublished { get; set; }

   26     }

The properties are all virtual so NHibernate can utilize the proxy pattern for performance reasons.  This will come more into play when use the Authors table in following posts.

Creating the test

As a part of the buildup and teardown of my NHibernate tests, I will have each of my test create a session object that connects to the data base before the test starts and then close the session object once the test finishes.

    1 using News.Core.Data;

    2 using Microsoft.VisualStudio.TestTools.UnitTesting;

    3 using NHibernate;

    4 

    5 namespace News.Web.Tests

    6 {

    7     public class DatabaseBaseTest

    8     {

    9         private ISessionFactoryManager sessionFactoryManager = new TestSessionFactoryManager();

   10         protected ISession session;

   11 

   12 

   13 

   14         [TestInitialize]

   15         public void SetUp()

   16         {

   17             

   19             session = sessionFactoryManager.GetSessionFactory().OpenSession();

   20         }

   21 

   22         [TestCleanup]

   23         public void CleanUp()

   24         {

   25             session.Close();

   26             session = null;

   27         }

   28     }

   29 }

Now that I have Session I can create my first test.  This test will simply return 1 record from the NewsItem table by passing the NewsItemId parameter.

   78         [TestMethod()]

   79         public void GetNewsItemByItemIdShouldReturnMatchingTitle()

   80         {

   81             var target = new NHibernateDataProvider(session);

   82             const string expected = "test";

   83             const int itemId = 2;

   84             Assert.AreEqual(expected, target.GetNewsItemByItemId(itemId).Title);

   85         }

My database has a record which contains the Title value “test”.

The Repository

The data access code that gets the records looks like this:

   17         public NewsItemDto GetNewsItemByItemId(long newsItemId)

   18         {

   19             return _session.Get<NewsItemDto>(newsItemId);

   20 

   21         }

In the next post I will add the Authors table to the mix and some functionality retrieving those joined records.