You can put something like this in your app.config/web.config file :
in the configSections node :
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>
in the configuration node :
<log4net>
<appender name="NHibernateFileLog" type="log4net.Appender.FileAppender">
<file value="logs/nhibernate.txt" />
<appendToFile value="false" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n" />
</layout>
</appender>
<logger name="NHibernate.SQL" additivity="false">
<level value="DEBUG"/>
<appender-ref ref="NHibernateFileLog"/>
</logger>
</log4net>
And don’t forget to call
log4net.Config.XmlConfigurator.Configure();
at the startup of your application, or to put
[assembly: log4net.Config.XmlConfigurator(Watch=true)]
in the assemblyinfo.cs
In the configuration settings, set the “show_sql” property to true.