流畅的 NHibernate 映射

该 Fluent NHibernate 是一个库，以帮助你在使用 C#代码，而不是 XML 映射的实体映射。流畅的 NHibernate 使用 fluent pattern ，它基于创建映射的约定，它为你提供了可视工作室工具（如 intellisense）的强大功能，以改善你映射实体的方式。

在项目中添加 Nuget 的 Fluent NHibernate 引用，并添加一个 CustomerMap.cs 类：

namespace Project.Mappings
{
    public class CustomerMap : ClassMap<Customer>
    {
        public CustomerMap()
        {
            Table("CUSTOMERS");

            Id(x => x.Id).Column("Customer_Id").GeneratedBy.Native();
            
            //map a property while specifying the max-length as well as setting 
            //it as not nullable. Will result in the backing column having
            //these characteristics, but this will not be enforced in the model!
            Map(x => x.Name)
                .Length(16)
                .Not.Nullable();

            Map(x => x.Sex);

            Map(x => x.Weight);

            Map(x => x.Active);

            //Map a property while specifying the name of the column in the database
            Map(x => x.Birthday, "BIRTHDAY");

            //Maps a many-to-one relationship
            References(x => x.Company);

            //Maps a one-to-many relationship, while also defining which 
            //column to use as key in the foreign table.
            HasMany(x => x.Orders).KeyColumn("CustomerPk");
        }
    }
}

CustomerMap 类来自 ClassMap<T>，它是映射的基类，包含创建 T 实体映射所需的所有方法。Table 方法定义了你要映射的表名。Id 方法用于映射 primery key 列。Map 方法用于映射其他列。