Nlog database (SQL Server) logging in Sharepoint environment (you cannot use nloc.config) Author: Bartosz Kusiak

create_log_table.sql

CREATE TABLE [dbo].[Log] (
      [Id] [int] IDENTITY(1,1) NOT NULL,
      [Application] [nvarchar](50) NOT NULL,
      [Logged] [datetime] NOT NULL,
      [Level] [nvarchar](50) NOT NULL,
      [Message] [nvarchar](max) NOT NULL,
      [Logger] [nvarchar](250) NULL,
      [Callsite] [nvarchar](max) NULL,
      [Exception] [nvarchar](max) NULL,
    CONSTRAINT [PK_dbo.Log] PRIMARY KEY CLUSTERED ([Id] ASC)
      WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
  ) ON [PRIMARY]

program.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using NLog;
using NLog.Config;
using NLog.Targets;
using NLog.Web;

namespace Sample
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var config = new LoggingConfiguration();

            DatabaseTarget dbTarget = new DatabaseTarget();
            dbTarget.Name = "db";
            dbTarget.DBProvider = "System.Data.SqlClient";
            dbTarget.ConnectionString = @"Data Source=.;Initial Catalog=database;Integrated Security=True;";
            dbTarget.CommandText =
                @"insert into dbo.Log (
        Application, Logged, Level, Message,
        Logger, CallSite, Exception
        ) values (
        @Application, @Logged, @Level, @Message,
        @Logger, @Callsite, @Exception
        );";

            dbTarget.Parameters.Add(new DatabaseParameterInfo("@application", "$AspNetCoreNlog"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@logged", "${date}"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@level", "${level}"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@message", "${message}"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@logger", "${logger}"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@callSite", "${callsite:filename=true}"));
            dbTarget.Parameters.Add(new DatabaseParameterInfo("@exception", "${exception:tostring}"));

            config.AddTarget(dbTarget);

            var consoleTarget = new ColoredConsoleTarget("target1")
            {
                Layout = @"${date:format=HH\:mm\:ss} ${level} ${message} ${exception}"
            };
            config.AddTarget(consoleTarget);

            config.AddRuleForOneLevel(NLog.LogLevel.Error, dbTarget); // only errors to file
            config.AddRuleForAllLevels(consoleTarget); // all to console

            LogManager.Configuration = config;

            CreateWebHostBuilder(args).Build().Run();

        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>().
            ConfigureLogging(logging =>
            {
                logging.ClearProviders();
                logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
            })
           .UseNLog();
    }
}