Question

I am trying to redirect NHibernate’s sql to a separate file with the following configuration but with no success. Everything (with SQL queries) goes to the main file.
Can someone help?

 <log4net>
    <appender name="DebugSQL" type="log4net.Appender.FileAppender">
      <param name="File" value="nhsql.log"/>
      <param name="AppendToFile" value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern
          value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>
    <appender name="Main" type="log4net.Appender.FileAppender">
      <param name="File" value="nh.log"/>
      <param name="AppendToFile" value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern
          value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>

    <logger name="NHibernate.SQL">
      <level value="ALL" />
      <appender-ref ref="DebugSQL" />
    </logger>
    <root>
      <level value="DEBUG" />
      <appender-ref ref="Main" />
    </root>

  </log4net>

Answer 1

That root configuration is going to send everything to the Main appender, in addition to sending the SQL to a separate file. If you want to prevent the SQL from showing up in the main log file, you need to search for “filter” in the log4net manual: http://logging.apache.org/log4net/release/manual/configuration.html Those should go inside the configuration for the main appender.