前言

这一章是一个完整的NHibernate的Simple,原文中用Fluent NHibernate做映射,但我使用NHibernate3.2版本,所以3.2的Conformist代替Fluent NHibernate.

从这里我们将学习到使用NHibernate的一般步骤:

1.定义Model

2.映射Model

3.定义配置

4.1根据配置创建数据库

4.2根据配置BuildSessionFactory

5.用SessionFactory对象OpenSession

6.用session对象做数据库操作

1.定义Model

定义两个类Product,Category

public class Category{    public virtual int Id { get; set; }    public virtual string Name { get; set; }    public virtual string Description { get; set; }}

public class Product{    public virtual int Id { get; set; }    public virtual string Name { get; set; }    public virtual string Description { get; set; }    public virtual decimal UnitPrice { get; set; }    public virtual int ReorderLevel { get; set; }    public virtual bool Discontinued { get; set; }    public virtual Category Category { get; set; }}

创建两个类CategoryMap,ProductMap

public class ProductMap : ClassMapping<Product>{    public ProductMap()    {        this.Id(p => p.Id, map =>        {            map.Generator(Generators.Identity);        });        this.Property(p => p.Description);        this.Property(p => p.Discontinued);        this.Property(p => p.Name);        this.Property(p => p.ReorderLevel);        this.Property(p => p.UnitPrice);        this.ManyToOne(p => p.Category);    }}

上面主键自动递增,Product的Category属性用ManyToOne映射

3.定义配置

public Form1(){    InitializeComponent();    configuration.DataBaseIntegration(        x =>        {            x.Dialect<SQLiteDialect>();            x.Driver<SQLite20Driver>();            x.ConnectionString = connString;        });    var mapper = new ModelMapper();    mapper.AddMapping<ProductMap>();    mapper.AddMapping<CategoryMap>();    var hbmMapping = mapper.CompileMappingForAllExplicitlyAddedEntities();    configuration.AddMapping(hbmMapping);    Debug.WriteLine(hbmMapping.AsString());}

这里做了几件事,设置数据库方言,数据库驱动,数据库连接字符串,把映射添加到配置中.

Debug.WriteLine输出的xml映射:

View Code

4.1根据配置创建数据库

有了配置就可以生成数据库

private void btCreateDataBase_Click(object sender, EventArgs e){    var sc = new SchemaExport(configuration);    sc.SetOutputFile(@"db.sql").Execute(false, false, false);    sc.Create(false, true);}

生成的数据库关系图

4.2根据配置BuildSessionFactory

有了配置就可以BuildSessionFactory

private ISessionFactory CreateSessionFactory(){    return configuration.BuildSessionFactory();}

5.用SessionFactory对象打开Session

有了ISessionFactory 就可以OpenSession

private void btnCreateSession_Click(object sender, EventArgs e){    var factory = CreateSessionFactory();    using (var session = factory.OpenSession())    {        // do something with the session    }}

6.用session对象做数据库操作

有了ISession对象,就像做数据库操作,可以把ISession对象想象成对象化的数据库

添加

private void btAddCategory_Click(object sender, EventArgs e){    var factory = CreateSessionFactory();    using (var session = factory.OpenSession())    {        var category = new Category        {            Name = txtCategoryName.Text,            Description = txtCategoryDescription.Text        };        var id = session.Save(category);        MessageBox.Show(id.ToString());    }}

查询

private void btLoadAll_Click(object sender, EventArgs e){    var factory = CreateSessionFactory();    using (var session = factory.OpenSession())    {        var categories = session.Query<Category>()        .OrderBy(c => c.Id)        .Select(c => c.Name + "-" + c.Description).ToArray();        lbCategory.DataSource = categories;    }}

NHibernate 3 Beginner's Guide