以编程方式将数据库参数添加到NLog

Question

I want to log message to my database by NLog. Suppose I have the database ready.

    var dbTarget = new DatabaseTarget();
    dbTarget.Name = "test";
    dbTarget.ConnectionString = loggerModel.connection_string; 
    dbTarget.CommandText = "insert into NlogLogTable(LogDate,LogLevel,LogLogger,LogMessage,LogMachineName,LogUserName,LogCallSite,LogThreadId,LogThreadName,LogException,LogStackTrace) values(@LogDate,@LogLevel,@LogLogger,@LogMessage,@LogMachineName,@LogUserName,@LogCallSite,@LogThreadId,@LogThreadName,@LogException,@LogStackTrace);";
    var dateTime = DateTime.Now.ToString();
    var dateTimeOffset = DateTimeOffset.Now.ToString();
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogDate", new NLog.Layouts.SimpleLayout("${LogDate}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogLevel", new NLog.Layouts.SimpleLayout("${LogLevel}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogLogger", new NLog.Layouts.SimpleLayout("${LogLogger}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogMessage", new NLog.Layouts.SimpleLayout("${LogMessage}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogMachineName", new NLog.Layouts.SimpleLayout("${LogMachineName}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogUserName", new NLog.Layouts.SimpleLayout("${LogUserName}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogCallSite", new NLog.Layouts.SimpleLayout("${LogCallSite}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogThreadId", new NLog.Layouts.SimpleLayout("${LogThreadId}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogThreadName", new NLog.Layouts.SimpleLayout("${LogThreadName}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogException", new NLog.Layouts.SimpleLayout("${LogException}")));
    dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogStackTrace", new NLog.Layouts.SimpleLayout("${LogStackTrace}")));

The thing is that I don't know how to pass the parameters to it. Let's say LogDate is today's datetime. Also I have command timeout (milliseconds) value, I am not sure how to pass it as well.

Answer 1

There are various options to pass LogDate and other custom values.

1. Use the ${event-properties:LogDate} and add the properties to your logEvent. (see EventProperties-Layout-Renderer .
2. Use the ${date} layout renderer, like ${date:format=yyyyMMdd}
3. Use the ${mdc:item=String} or ${gdc:item=String}

For the command timeout you can use 2. or 3.

All possible values are listed on the NLog wiki .

edit: the code for command timeout

Add to the target:

dbTarget.Parameters.Add(new DatabaseParameterInfo("@LogDate", new NLog.Layouts.SimpleLayout("${event-properties:CommandTimeout}")));

When writing the event (using the fluent interface, see 3 )

var logger = LogManager.GetCurrentClassLogger();
logger.Info()
    .Message("This is a test fluent message '{0}'.", DateTime.Now.Ticks)
    .Property("CommandTimeout", YourCommandTimeout)
    .Write();