使用NHibernate 注意要点

1. 应用层的工程的App.config也要有NHibernate相关的配置。

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="nhibernate" type="System.Configuration.NameValueSectionHandler, System,Version=1.0.5000.0,Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  </configSections>
  <nhibernate>
    <add         key="hibernate.connection.provider"       value="NHibernate.Connection.DriverConnectionProvider" 
        />
    <add 
key="hibernate.dialect"                      
value="NHibernate.Dialect.MsSql2000Dialect" 
        />
    <add key="hibernate.show_sql" value="false"/>
    <add 
    key="hibernate.connection.driver_class"        value="NHibernate.Driver.SqlClientDriver" 
        />
    <add 
            key="hibernate.connection.connection_string"         value="Server=.\SQLEXPRESS;Initial Catalog=DatabaseName;Integrated Security=SSPI" 
        />
  </nhibernate>
</configuration>

2. 数据库设计当中，表名，字段名不能有数据库的关键字，如：user, group.....字段名最好不与表名相同

3.实体映射文件（*.hbm.xml)要设置为Embeded Resource（嵌入式资源）文件。
4.对于one-to-many, 配置要用set, 实体类要用Iesi.Collections.ISet。
例如：
Role.hbm.xml

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
  <class name="Common.Entity.Role,Common" table="Role">
    <id name="RoleKey" type="Int32">
      <generator class="assigned" />
    </id>
    <property name="RoleName" type="String"/>
    <set name="UserMembers" inverse="true" cascade="all">
      <key column="RoleKey"/>
      <one-to-many class="Common.Entity.User,Common"/>
    </set>
  </class>
</hibernate-mapping>

Role.cs

 public class Role
    {
        private int roleKey;

        private string roleName;

        private ISet userMembers;

        public string RoleName
        {
            get
            {
                return roleName;
            }
            set
            {
                roleName = value;
            }
        }

        public int RoleKey
        {
            get
            {
                return roleKey;
            }
            set
            {
                roleKey = value;
            }
        }

        public ISet UserMembers
        {
            get
            {
                if (userMembers == null)
                {
                    userMembers = new HashedSet();
                }
                return userMembers;
            }
            set
            {
                userMembers = value;
            }
        }
    }

5.实体类一定要override Equals方法与GetHashcode方法。

6.对数据进行插入、修改、删除要使用事务：
ITransaction tran=session.BegionTransaction();
//Do something
tran.Commit();