NHibernate 3 Beginner's Guide
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; }
}
类关系图:
2.映射Model
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());
}
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;
}
}
