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MySqlConnector

Logging

MySqlConnector 2.3.0 and later supports logging through the standard Microsoft.Extensions.Logging interfaces.

Console Programs

To set up logging in MySqlConnector, create your ILoggerFactory as usual, and then configure a MySqlDataSource with it. Any use of connections handed out by the data source will log via your provided logger factory.

The following shows a minimal console application logging to the console via Microsoft.Extensions.Logging.Console:

using Microsoft.Extensions.Logging;
using MySqlConnector;

// Create a Microsoft.Extensions.Logging LoggerFactory, configuring it with the providers,
// log levels and other desired configuration.
var loggerFactory = LoggerFactory.Create(builder => builder.AddConsole());

// Create a MySqlDataSourceBuilder, configuring it with our LoggerFactory.
var dataSourceBuilder = new MySqlDataSourceBuilder("Host=localhost;User ID=root;Password=pass");
dataSourceBuilder.UseLoggerFactory(loggerFactory);
await using var dataSource = dataSourceBuilder.Build();

// Any connections handed out by the data source will log via the LoggerFactory:
await using var connection = await dataSource.OpenConnectionAsync();
await using var command = new MySqlCommand("SELECT 1", connection);
_ = await command.ExecuteScalarAsync();

ASP.NET and Dependency Injection

If you’re using ASP.NET, you can use the additional MySqlConnector.DependencyInjection package, which provides seamless integration with dependency injection and logging:

var builder = WebApplication.CreateBuilder(args);
builder.Logging.AddConsole();
builder.Services.AddMySqlDataSource("Host=localhost;User ID=root;Password=pass");

The AddMySqlDataSource method registers a data source with the DI container. This data source automatically uses the logger factory configured by ASP.NET by default. This allows your endpoints to get injected with MySQL connections which log to the application’s logger factory.

Global Logging

Migrating from Global Logging

In MySqlConnector 2.4.0, the MySqlConnectorLogManager.Provider API has been deprecated. Follow these instructions to migrate to the new logging API.

With the deprecated logging framework, you may have had code that looked like this:

log4net.Config.XmlConfigurator.Configure();
MySqlConnectorLogManager.Provider = new Log4netLoggerProvider();
using var connection = new MySqlConnection(connectionString);

To migrate to the new logging API, you will need to:

This will look like the following, depending on your exact configuration:

// create a LoggerFactory and configure it with the desired logging framework
// use ONLY ONE of the "Add" methods below, depending on your logging framework
var loggerFactory = LoggerFactory.Create(builder =>
  // if you just want console logging
  builder.AddConsole();

  // connect to log4net via Microsoft.Extensions.Logging.Log4Net.AspNetCore
  builder.AddLog4Net(new Log4NetProviderOptions
  {
    UseWebOrAppConfig = true, // set this if you're storing your settings in Web.config instead of log4net.config
    ExternalConfigurationSetup = true, // set this instead if you're initializing log4net yourself
    // see other options at https://github.com/huorswords/Microsoft.Extensions.Logging.Log4Net.AspNetCore
  }));

  // connect to NLog via NLog.Extensions.Logging
  builder.AddNLog();

  // connect to Serilog via Serilog.Extensions.Logging
  builder.AddSerilog(dispose: true);
);

// now create a MySqlDataSource and configure it with the LoggerFactory
using var dataSource = new MySqlDataSourceBuilder(yourConnectionString)
  .UseLoggerFactory(loggerFactory)
  .Build();

// create all MySqlConnection objects via the MySqlDataSource, not directly
// DON'T: using var connection = new MySqlConnection(yourConnectionString);
using var connection = dataSource.CreateConnection();

// you can also create open connections
using var connection = await dataSource.OpenConnectionAsync();

Deprecated Logging Framework

The following information is for MySqlConnector versions prior to 2.3.0. The global logging interface that is described is deprecated and shouldn't be used in new code.

MySqlConnector implements a custom logging framework with the IMySqlConnectorLogger and IMySqlConnectorLoggerProvider interfaces. To connect MySqlConnector to an existing logging framework, write an implementation of IMySqlConnectorLoggerProvider that adapts the existing logging framework, and install it by setting MySqlConnector.Logging.MySqlConnectorLogManager.Provider = provider;.

The MySqlConnectorLogManager.Provider property may only be set once, and must be set before any other MySqlConnector library methods are called.

Trace-level logging is useful for diagnosing problems with MySqlConnector itself; it is recommended that applications limit MySqlConnector logging to Info or higher.

Existing Logging Providers

There are NuGet packages that adapt MySqlConnector logging for popular logging frameworks.

log4net

Install MySqlConnector.Logging.log4net.

Add the following line of code to your application startup routine:

MySqlConnectorLogManager.Provider = new Log4netLoggerProvider();

To reduce the verbosity of MySqlConnector logging, add the following element to your log4net config:

<log4net>
  ...
  <logger name="MySqlConnector">
    <level value="WARN" /> <!-- or "INFO" -->
  </logger>

Microsoft.Extensions.Logging

Install MySqlConnector.Logging.Microsoft.Extensions.Logging.

Add the following line of code to your Startup.Configure method:

MySqlConnectorLogManager.Provider = new MicrosoftExtensionsLoggingLoggerProvider(loggerFactory);

NLog

Install MySqlConnector.Logging.NLog.

Add the following line of code to your application startup routine:

MySqlConnectorLogManager.Provider = new NLogLoggerProvider();

Serilog

Install MySqlConnector.Logging.Serilog.

Add the following line of code to your application startup routine:

MySqlConnectorLogManager.Provider = new SerilogLoggerProvider();