C# – Log4Net, how to add a custom field to the logging

appenderclog4net

I use the log4net.Appender.AdoNetAppender appender.
My log4net table are the following fields [Date],[Thread],[Level],[Logger],[Message],[Exception]

I would need to add another field to the log4net table (e.g SalesId), but how would I specify in my xml and in code to log the "SalesId" when logging a Error or Info message?

e.g. log.Info("SomeMessage", SalesId)

Here's the log4net xml

  <appender name="SalesDBAppender" type="log4net.Appender.AdoNetAppender">
    <bufferSize value="1" />
    <connectionType value ="System.Data.SqlClient.SqlConnection" />
    <connectionString value="Data Source=..." />
    <commandText value="INSERT INTO Log4Net ([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>

Best Answer

1) Modify the command text: INSERT INTO Log4Net ([Date],[Thread],[Level],[Logger],[Message],[Exception],[MyColumn]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception, @CustomColumn)

2) Add the parameter definition for the custom column:

<parameter>
   <parameterName value="@CustomColumn"/>
   <dbType value="String" />
   <size value="255" />
   <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%property{CustomColumn}" />
  </layout>
</parameter>

3) Then use one of log4net’s contexts to transfer values to the parameter:

// thread properties...
log4net.LogicalThreadContext.Properties["CustomColumn"] = "Custom value";
log.Info("Message"); 

// ...or global properties
log4net.GlobalContext.Properties["CustomColumn"] = "Custom value";
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