如何编写自定义nHibernate方言？

Question

我正在将NHibernate与旧的rdbms规则引擎一起使用。我正在使用GenericDialect，但生成的某些sql无法正常工作。如果我需要为此规则引擎编写自定义方言，该如何开始？

Answer 1

这是一个方言示例：

using System;
using System.Collections.Generic;
using System.Web;

/// 
/// This class ensures that the tables created in our db are handling unicode properly.
/// 
public class NHibernateMySQL5InnoDBDialect : NHibernate.Dialect.MySQL5Dialect
{
    public override String TableTypeString { get { return " ENGINE=InnoDB DEFAULT CHARSET=utf8"; } }
}

它所在的程序集引用了NHibernate.dll

hibernate.cfg.dll（请注意，我这里没有设置’connection.connection_string’属性，这是我的特定设置，通常您在这里会有连接字符串）：

<?xml version="1.0" encoding="utf-8"?>
<!-- This is the ByteFX.Data.dll provider for MySql -->
<hibernate-configuration  xmlns="urn:nhibernate-configuration-2.2" >
  <session-factory name="NHibernate.Test">
    <property name="connection.driver_class">NHibernate.Driver.MySqlDataDriver</property>
    <property name="dialect">NHibernateMySQL5InnoDBDialect, Assembly1</property>
    <property name="proxyfactory.factory_class">NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu</property>
  </session-factory>
</hibernate-configuration>

在某些设置中，方言行是

<property name="dialect">Assembly1.NHibernateMySQL5InnoDBDialect, Assembly1</property>

和创建ISessionFactory的代码：

NHibernate.Cfg.Configuration cfg = new NHibernate.Cfg.Configuration();
cfg.Configure();
cfg.Properties["connection.connection_string"] = ConnectionStringForDatabase();
cfg.AddDirectory(PathToMappingsIfYouUseNonStandardDirectory);//not needed if using embedded resources
return cfg.BuildSessionFactory();