You need to create the database and the Log table yourself.
If you want to diagnose possible issues with log4net, you can create a diagnostic trace by adding this to your .config file:
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add
name="textWriterTraceListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="C:\whatever\your\path\is\log4net.txt" />
</listeners>
</trace>
</system.diagnostics>
and adding the debug switch:
<appSettings>
<add key="log4net.Internal.Debug" value="true"/>
</appSettings>
solved Configuring log4net to write on a database