Nlog Error when writing to database, what is the correct config for Nlog in asp core 2?

Question

what is the correct config for Nlog in asp.net core. I followed this tutorial and the loggers are working properly except for writing in the database. I keep getting this error (internal nlog),

2017-08-30 18:05:39.8956 Error Error when writing to database. Exception: System.Data.SqlClient.SqlException (0x80131904): Invalid object name 'dbo.Log'. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite, String method) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite, String methodName) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at NLog.Targets.DatabaseTarget.WriteEventToDatabase(LogEventInfo logEvent) at NLog.Targets.DatabaseTarget.Write(LogEventInfo logEvent) ClientConnectionId:fa24cf47-f585-4d2d-af29-134c8b4be13c Error Number:208,State:1,Class:16

the table dbo.Log exists in the database (ARTCore).

my nlog.config

<?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"
      internalLogLevel="Warn"
      internalLogFile="D:\SQLCORE\RazorCore\ArtCore\ArtCore\Logs\internal-nlog.txt">
  <targets>
    <target xsi:type="File" name="allfile" fileName="${var:configDir}\nlog-all.log"
                    layout="${longdate}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|${message} ${exception}" />

    <target xsi:type="File" name="ownFile-web" fileName="${var:configDir}\nlog-own.log"
             layout="${longdate}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|  ${message} ${exception}" />

    <target xsi:type="Null" name="blackhole" />
    <target name="ARTCore" xsi:type="Database" >
      <commandText>
        insert into dbo.Log (
        Application, Logged, [Level], Message,
        Logger, CallSite, Exception
        ) values (
        @Application, @Logged, @Level, @Message,
        @Logger, @Callsite, @Exception
        );
      </commandText>
      <parameter name="@application" layout="AspNetCoreNlog" />
      <parameter name="@logged" layout="${date}" />
      <parameter name="@level" layout="${level}" />
      <parameter name="@message" layout="${message}" />
      <parameter name="@logger" layout="${logger}" />
      <parameter name="@callSite" layout="${callsite:filename=true}" />
      <parameter name="@exception" layout="${exception:tostring}" />
    </target>
  </targets>
  <rules>
    <logger name="*" minlevel="Trace" writeTo="allfile" />
    <logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />
    <logger name="*" minlevel="Trace" writeTo="ownFile-web" /> 
    <logger name="*" minlevel="Trace" writeTo="ARTCore" />
  </rules>
</nlog>

appsettings.json:

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  },
  "ElasticsearchUrl": "http://localhost:44303",
  "ConnectionStrings": {
    "ARTCore": "Server=****;Database=ARTCore;Trusted_Connection=True;MultipleActiveResultSets=true;"
  }
}

Registration

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddNLog();
            app.AddNLogWeb();
            env.ConfigureNLog("nlog.config");
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseBrowserLink();
                app.UseDatabaseErrorPage();

            }
            else
            {
                app.UseExceptionHandler("/Error");
            }
            app.UseStaticFiles();
            app.UseAuthentication();
            //LogManager.ReconfigExistingLoggers();
            LogManager.Configuration.Variables["ConnectionStrings"] = Configuration.GetConnectionString("ARTCore");
            LogManager.Configuration.Variables["configDir"] = "D:\\SQLCORE\\RazorCore\\ArtCore\\ArtCore\\Logs";
            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller}/{action=Index}/{id?}");
            });
        }

What am I missing here?

Answer 1

Solved by,

adding connectionString="${var:ConnectionStrings}" , and including <PackageReference Include="System.Data.SqlClient" Version="4.4.0" />

The working config in startup.csis,

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            env.ConfigureNLog("nlog.config");

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseBrowserLink();
                app.UseDatabaseErrorPage();

            }
            else
            {
                app.UseExceptionHandler("/Error");
            }
            app.UseStaticFiles();
            app.UseAuthentication();
            loggerFactory.AddNLog();
            app.AddNLogWeb();
            LogManager.Configuration.Variables["ConnectionStrings"] = Configuration.GetConnectionString("ARTCore");
            LogManager.Configuration.Variables["configDir"] = "D:\\SQLCORE\\RazorCore\\ArtCore\\ArtCore\\Logs";
            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller}/{action=Index}/{id?}");
            });
        }

and the nlog.config is

<?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"
      keepVariablesOnReload="true"
      internalLogLevel="Warn"
      throwExceptions="false"
      internalLogFile="D:\SQLCORE\RazorCore\ArtCore\ArtCore\Logs\internal-nlog.txt">
  <targets>
    <target xsi:type="File" name="allfile" fileName="${var:configDir}\nlog-all.log"
                    layout="${longdate}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|${message} ${exception}" />

    <target xsi:type="File" name="ownFile-web" fileName="${var:configDir}\nlog-own.log"
             layout="${longdate}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|  ${message} ${exception}" />

    <target xsi:type="Null" name="blackhole" />
    <target name="ARTCore" xsi:type="Database" connectionString="${var:ConnectionStrings}" >
      <commandText>
        insert into dbo.Log (
        Application, Logged, [Level], Message,
        Logger, CallSite, Exception
        ) values (
        @Application, @Logged, @Level, @Message,
        @Logger, @Callsite, @Exception
        );
      </commandText>
      <parameter name="@application" layout="AspNetCoreNlog" />
      <parameter name="@logged" layout="${date}" />
      <parameter name="@level" layout="${level}" />
      <parameter name="@message" layout="${message}" />
      <parameter name="@logger" layout="${logger}" />
      <parameter name="@callSite" layout="${callsite:filename=true}" />
      <parameter name="@exception" layout="${exception:tostring}" />
    </target>
  </targets>
  <rules>
    <logger name="*" minlevel="Trace" writeTo="allfile" />
    <logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />
    <logger name="*" minlevel="Trace" writeTo="ownFile-web" /> 
    <logger name="*" minlevel="Trace" writeTo="ARTCore" />
  </rules>
</nlog>

Reference.