You should be able to set the threshold
property of each appender separately and include them in the same root.
<appender name="filelogAppender" type="log4net.Appender.RollingFileAppender">
<threshold value="Error" />
</appender>
<appender name="dblogAppender" type="log4net.Appender.AdoNetAppender">
<threshold value="Info" />
</appender>
<root>
<appender-ref ref="filelogAppender" />
<appender-ref ref="dblogAppender" />
</root>