Implementation of Logging in SQL Server Database for Dot Net Core Applications.

This repository contains Implementation of ASP.NET Core Logger Provider in SQL Server Database. It enables you to log the information in SQL Database table. For general ASP.NET Core logger implementation, visit here.

Install the Daenet.Common.Logging.Sql NuGet Package in your application.

The SqlServerLogger needs to be configured and initialized.

ASP.NET Core Web Application

public static IWebHost BuildWebHost(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
            .ConfigureLogging((hostingContext, logging) =>
            {
                var loggerSection = hostingContext.Configuration.GetSection("Logging");
                logging.AddConfiguration(loggerSection);
                logging.AddConsole();
                logging.AddDebug();
                logging.AddSqlServerLogger((sett) =>
                {
                    sett.SetSqlServerLoggerSettings(loggerSection);
                });
            })
                .Build();
    }

Console Application

  public IConfigurationRoot Configuration;
  var builder = new ConfigurationBuilder().AddJsonFile("appsettings.json");
  Configuration = builder.Build();

  ILoggerFactory loggerFactory = new LoggerFactory().AddSqlServerLogger(Configuration.GetSection("Logging"));
  ILogger logger = loggerFactory.CreateLogger<SqlServerLoggerTests>();

In the appsettings.json, the SqlProvider part needs to be added to Logging.

{
  "Logging": {
    "IncludeScopes": true,
    "Debug": {
      "LogLevel": {
        "Default": "Information"
      }
    },
    "Console": {
      "LogLevel": {
        "Default": "Warning"
      }
    },
    "SqlProvider": {
      "LogLevel": {
        "Default": "Information"
      },
      "ConnectionString": "",
      "TableName": "SqlLog",
      "BatchSize": 1,
      "InsertTimerInSec": 60,
      "IncludeExceptionStackTrace": false,
      "IgnoreLoggingErrors": false,
      "ScopeSeparator": "=>"
    }
  }
}

LogLevel configuration are done on global and logger level see Introduction to Logging in ASP.NET Core

IncludeScope flag is used when the logging is to be done inside one particular scope. IncludeScope when set to true, and initialized inside code with beginScope("scopeStatement") adds scope id to every logged statement which is added to database under column "Scope". Following example illustrates using scope in logging when IncludeScopes flag is set to true.

 using (m_Logger.BeginScope($"Scope Begins : {Guid.NewGuid()}"))
 {
   //Here log something
 }

This will add "Scope begins : new hexadecimal guid" for every object instance of the class where scope is began.

ConnectionString is ADO.NET connection string for SQL authentication.

TableName is name of the table where logger should log.

BatchSize Decides when to write messages to the database. If BatchSize > 1 then we fill a List and wait till list count reaches BatchSize or Insert to DB is triggered by InsertTimerInSec. If BatchSize > 1 writing the data to db is async.

InsertTimerInSec Time elapsed when logger writes to table even BatchSize isn't reached.

(REMOVED in 1.0.7.2) CreateTblIfNotExist flag when set to true, gives the logger ability to create the table of table name that is provided in configuration in case it is not already available in database. This flag is useful while testing the logger in development environment.

IncludeExceptionStackTrace flag is currently not implemented and complete exception is logged in table regardless of this flag.

IgnoreLoggingErrors flag is to decide if the application should fail if an exception occurs on logging. When set to false, the logger at the moment logs these errors in debug console. **WARNING: Only works if BatchSize = 1

To log the error in SQL database, A table must be present in database with predefined column format. Following columns are filled by logger -

• Id - Unique id of each entry, automatically incremented
• EventId - Event Id of each log.
• Type - Log level
• Scope - Scope information if scoping is enabled and used
• Message - Log message
• Exception - Complete exception in case of error
• TimeStamp - Timestamp of log
• CategoryName - Namespace from where the log is logged

Following query will create a new table in SQL Database with above parameters, and should be used as a reference query for default format.

CREATE TABLE [dbo].[YourTableName](
       [Id] [bigint] IDENTITY(1,1) NOT NULL,
       [EventId] [int] NULL,
       [Type] [nvarchar](15) NOT NULL,
       [Scope] [nvarchar](MAX) NULL,
       [Message] [nvarchar](max) NOT NULL,
       [Exception] [nvarchar](max) NULL,
       [TimeStamp] [datetime] NOT NULL,
       [CategoryName] [nvarchar] (max) NULL,
CONSTRAINT [PK_YourTableName] 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] TEXTIMAGE_ON [PRIMARY]

It's possible to log parameters to database, too. In this example we want to log the RequestId and the scope to the database. For this to work, you have to create the columns of course.

This configuration has to be apppended to the SqlProvider section in Logging.

Here is an example of how to log the 2 .NET Core internal logging parameters. You can extend this, with the parameters you use in your logging. A good example here is {method} for logging the method name in a general way.

"ScopeColumnMapping": {
        "RequestId": "RequestId",
        "SCOPEPATH": "Scope"
      }

It is also possible to use your own custom logging format by providing loggingFormatter