How do I configure NLog to write to a database?

Question

I'm trying to get NLog to write to a database, however with my current code it throws an exception when I attempt to debug, the exception is: The type initializer for 'NotifyIcon.Program' threw an exception.

my NLog configuration file code is below, as this seems to be causing the issue as it's the only code I've changed.

<?xml version="1.0" encoding="utf-8" ?> <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" autoReload="true">    <!--    See http://nlog-project.org/wiki/Configuration_file    for information on customizing logging rules and outputs.    -->   <targets>     <!-- add your targets here -->      <target name="database" xsi:type="Database" />     <target xsi:type="Database"           name="String"           dbUserName="Layout"           dbProvider="sqlserver"           useTransactions="false"           connectionStringName="String"           connectionString="Data Source=AC-02\SQLEXPRESS;Initial Catalog=master;Integrated Security=True"           keepConnection="true"           dbDatabase="Layout"           dbPassword="Layout"           dbHost="Layout"           installConnectionString="Layout"           commandText="INSERT INTO Logs (Machine_Name, Username, Logon_Time, Screensaver_On, Screensaver_Off, Logoff_Time, Program_Start) Values @MachineName, @Username, @LogonTime, @Screensaver_On, @Screensaver_Off, @LogoffTime, @ProgramStart "/>    </targets>    <rules>      <logger name="*" minlevel="Trace" writeTo="database" />    </rules> </nlog> 

any and all help would be greatly appreciated =]

Answer 1

You seem to be missing the parameters that are to be inserted.

See the examples at http://justinpdavis.blogspot.com/2010/04/logging-to-database-with-nlog.html

The nLog web page doesn't make it very clear that these are required, but if you squint your eyes and read https://github.com/nlog/NLog/wiki/Database-target you should find that they are required.

Answer 2

A simple example,

Config:

<target type="Database" name="database" connectionstring="Server=localhost;Database=NLog;Trusted_Connection=True;">   <commandText>     INSERT INTO NLogEntries ([Origin], [Message], [LogLevel],[CreatedOn],[OrderId]) VALUES (@Origin,@Message,@LogLevel,@Date, @OrderId);   </commandText>   <parameter name="@Date" layout="${date}" dbType="DbType.Date"/>   <parameter name="@Origin" layout="${callsite}"/>   <parameter name="@LogLevel" layout="${level}"/>   <parameter name="@message" layout="${message}"/>   <parameter name="@OrderId" layout="${event-properties:MyOrderId}" dbType="DbType.Int32"/> <!-- custom field! Note also the DB Type. Using Logger.WithProperty --> </target> 

Note, NLog 4.6 has also support for DbType - See https://nlog-project.org/2019/03/20/nlog-4-6-is-live.html