如何查看nHibernate生成的SQL？

<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
 <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%d [%t] %-5p %c - %m%n" />
  </layout>
</appender><logger name="NHibernate.SQL">
 <level value="DEBUG" />
  <appender-ref ref="ConsoleAppender" />
</logger>

public class SqlInterceptor : EmptyInterceptor
{
    public override NHibernate.SqlCommand.SqlString OnPrepareStatement(NHibernate.SqlCommand.SqlString sql)
    {
        Debug.WriteLine(sql.ToString());
        return sql;
    }
}

var configuration = new Configuration();
// 其他配置代码
var sessionFactory = configuration.BuildSessionFactory();
var session = sessionFactory.OpenSession(new SqlInterceptor());