AnimalService.cs

public class AnimalService : IAnimalService
{
    private readonly IDatabase _database;

    public AnimalService(IDatabase database)
    {
        _database = database;
    }

    public IEnumerable<Animal> GetAllAnimals()
    {
        return _database.Query(new GetAllAnimals());
    }

    public IEnumerable<Animal> GetAnimalsByCommonName(CommonName commonName)
    {
        return _database.Query(new GetAnimalsByCommonName(commonName));
    }

    public void Save(Animal animal)
    {
        _database.Execute(new SaveAnimal(animal));
    }
}

GetAllAnimals.cs

public class GetAllAnimals : IQuery<IList<Animal>>
{
    public IList<Animal> Execute(ISession session)
    {
        return session.Query<Animal>("SELECT * FROM Animals").ToList();
    }
}

ICommand.cs

public interface ICommand
{
    void Execute(ISession session);
}

IDapperContext.cs

public interface IDapperContext : IDisposable
{
    IDbConnection Connection { get; }
    T Transaction<T>(Func<IDbTransaction, T> query);
    IDbTransaction BeginTransaction();
    void Commit();
    void Rollback();
}

IQuery.cs

public interface IQuery<out T>
{
    T Execute(ISession session);
}

SaveAnimal.cs

public class SaveAnimal : ICommand
{
    private readonly Animal _animal;
    
    public SaveAnimal(Animal animal)
    {
        _animal = animal;
    }
    
    public void Execute(ISession session)
    {
        if (_animal.Id > 0)
        {
            session.Execute("UPDATE Animals SET Name = @Name, CommonName = @CommonName WHERE Id = @Id", new { _animal.Id, _animal.Name, _animal.CommonName });
            return;
        }
    
        session.Execute("INSERT INTO Animals (Name, CommonName) VALUES (@Name, @CommonName)", new { _animal.Name, _animal.CommonName });
    }
}