如何在log4net ADONetAppender中使用存储过程？

<log4net>
  <appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">
   <bufferSize value="1" />
   <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
   <connectionString value="data source=localhost;initial catalog=mydb;integrated security=false;persist security info=True;User ID=myuser;Password=mypassword" />
   <commandText value="INSERT INTO Log (Date, Thread, Level, Logger, Message, Exception) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
   <parameter>
     <parameterName value="@log_date" />
      <dbType value="DateTime" />
     <layout type="log4net.Layout.RawTimeStampLayout" />
    </parameter>
   <parameter>
     <parameterName value="@thread" />
      <dbType value="String" />
      <size value="255" />
     <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%thread" />
      </layout>
    </parameter>
   <parameter>
     <parameterName value="@log_level" />
      <dbType value="String" />
      <size value="50" />
     <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%level" />
      </layout>
    </parameter>
   <parameter>
     <parameterName value="@logger" />
      <dbType value="String" />
      <size value="255" />
     <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%logger" />
      </layout>
    </parameter>
   <parameter>
     <parameterName value="@message" />
      <dbType value="String" />
      <size value="4000" />
     <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%message" />
      </layout>
    </parameter>
   <parameter>
     <parameterName value="@exception" />
      <dbType value="String" />
      <size value="2000" />
     <layout type="log4net.Layout.ExceptionLayout" />
    </parameter>
  </appender>
  <root>
   <level value="DEBUG" />
    <appender-ref ref="ADONetAppender" />
  </root>
</log4net>

CREATE PROCEDURE sp_InsertLog
    @log_date DATETIME,
    @thread NVARCHAR(255),
    @log_level NVARCHAR(50),
    @logger NVARCHAR(255),
    @message NVARCHAR(4000),
    @exception NVARCHAR(2000)
AS
BEGIN
    INSERT INTO Log (Date, Thread, Level, Logger, Message, Exception)
    VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)
END

private static readonly ILog log = LogManager.GetLogger(typeof(Program));

static void Main(string[] args)
{
    log.Debug("This is a debug message");
    log.Info("This is an info message");
    log.Warn("This is a warning message");
    log.Error("This is an error message");
    log.Fatal("This is a fatal message");
}