C# – Best practices to generate schema for production with NHibernate

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I am now ready to use NHibernate to persist my data layer access. I used DDD until that point and I use fake for unit tests and for the test site.

I know that I can use SchemaExport for unit/integration tests of my NHibernate concrete repositories but how should I generate the schema to be used for the test site ?

Should I create a special class in my tests that create the schema and insert the static data or should I generate the schema at the launch of the site if the database is not created ?

Best Answer

Personally I like to use a small console application which loads all the mappings and executes a SchemaExport as below:

new SchemaExport(config).Execute(ddlScript => {
    using (var writer = new StreamWriter(fileName, true))
    {
        writer.Write(ddlScript);
        writer.Flush();
    }
}, false, false);

This console app runs as a step of the build script and the DDL script file then gets picked up by WiX and is included in the MSI package (which generates the whole database at install time).

Related Solutions

Sql – Strategies for using NHibernate to generate a schema

When testing, we use NHibernate to create the database, then a series of builders to create the data for each test fixture. We also use Sqlite for these tests, so they are lightening fast.

Our builders look a something like this:

public class CustomerBuilder : Builder<Customer>
{
   string firstName;
   string lastName;
   Guid id = Guid.Empty;

   public override Customer Build()
   {
      return new Customer() { Id = id, FirstName = firstName, LastName = }
   }

   public CustomerBuilder WithId(Guid newId)
   {
      id= newId;
      return this;
   }

   public CustomerBuilder WithFirstName(string newFirstName)
   {
      firstName = newFirstName;
      return this;
   }

   public CustomerBuilder WithLastName(string newLastName)
   {
      lastName = newLastName;
      return this;
   }
}

and usage:

var customer = new CustomerBuilder().WithFirstName("John").WithLastName("Doe").Build();

Because every line of code is written with TDD, we build up a comprehensive suite of data from scatch and will generally refactor some of it to factories that will wrap the above and make it a breeze to get dummy data in.

R – Implementing NHibernate Unit Test to Generate Schema with VB.NET/MBUnit

The section declares the name of an assembly containing class declarations and mapping files. The mapping files contain the metadata for the mapping of the POCO class to a database table (or multiple tables).

On the other hand you've got

cfg.AddAssembly(GetType(Todd.Core.Product).Assembly)

in your "GenerateSchema_Fixture". This means that NHibernate will load all of the mapping files contained in an Assembly.

You've to decide which way you want to provide the information for NHibernate.

If you want to do everything programmatically, I would sugest the use FluentNHibernate. You declaring everything over a fluent interface and don't have to think about XML files. (fluentnhibernate.org).

Best Answer

Related Solutions

Sql – Strategies for using NHibernate to generate a schema

R – Implementing NHibernate Unit Test to Generate Schema with VB.NET/MBUnit

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