Use with ASP.NET Core Dependency Injection

MySqlConnector includes dependency injection support in the core package. This tutorial shows how to register MySqlDataSource and MySqlConnection, customize the data source builder, and use keyed services for multiple databases.

1. Install MySqlConnector

Install the MySqlConnector NuGet package:

dotnet add package MySqlConnector

If you’re upgrading from the old package, uninstall MySqlConnector.DependencyInjection first:

dotnet remove package MySqlConnector.DependencyInjection
dotnet add package MySqlConnector

If MySqlConnector is already installed, only the dotnet remove package MySqlConnector.DependencyInjection command is needed.

2. Register a Data Source

Add using MySqlConnector; to Program.cs, then register a data source:

builder.Services.AddMySqlDataSource(builder.Configuration.GetConnectionString("Default")!);

This registers MySqlDataSource and MySqlConnection with the DI container. It also uses the ILoggerFactory configured by ASP.NET Core automatically; for more information, see Logging.

3. Inject `MySqlConnection`

The registered MySqlConnection is transient, so it can be injected into controllers, minimal APIs, and other services:

app.MapGet("/", async (MySqlConnection connection) =>
{
    await connection.OpenAsync();
    await using var command = connection.CreateCommand();
    command.CommandText = "SELECT name FROM users LIMIT 1";
    return "Hello World: " + await command.ExecuteScalarAsync();
});

4. Inject `MySqlDataSource`

Inject MySqlDataSource directly if you need more than one connection or want to control when connections are opened:

app.MapGet("/", async (MySqlDataSource dataSource) =>
{
    await using var connection1 = await dataSource.OpenConnectionAsync();
    await using var connection2 = await dataSource.OpenConnectionAsync();
    // use the two connections...
});

5. Configure `MySqlDataSourceBuilder`

Use the AddMySqlDataSource overload that takes Action<MySqlDataSourceBuilder> to configure the data source:

builder.Services.AddMySqlDataSource(
    "Server=server;User ID=test;Password=test;Database=test",
    dataSourceBuilder => dataSourceBuilder.UseRemoteCertificateValidationCallback(
        (sender, certificate, chain, sslPolicyErrors) => { /* custom logic */ }));

Any MySqlDataSourceBuilder APIs can be used here, such as UseName, UseLoggerFactory, or TLS configuration methods.

6. Use Other Services During Configuration

Use the AddMySqlDataSource overload that takes Action<IServiceProvider, MySqlDataSourceBuilder> when configuration depends on other registered services:

builder.Services.AddMySqlDataSource(
    builder.Configuration.GetConnectionString("Default")!,
    (serviceProvider, dataSourceBuilder) =>
    {
        var hostEnvironment = serviceProvider.GetRequiredService<IHostEnvironment>();
        dataSourceBuilder.UseName(hostEnvironment.ApplicationName);
    });

This is useful when the data source name, certificates, or other options depend on application services or environment-specific configuration.

7. Register Keyed Data Sources

Use AddKeyedMySqlDataSource to register multiple MySqlDataSource instances as keyed services:

builder.Services.AddKeyedMySqlDataSource("users", builder.Configuration.GetConnectionString("Users")!);
builder.Services.AddKeyedMySqlDataSource("products", builder.Configuration.GetConnectionString("Products")!);

app.MapGet("/users/{userId}", async (int userId, [FromKeyedServices("users")] MySqlConnection connection) =>
{
    await connection.OpenAsync();
    await using var command = connection.CreateCommand();
    command.CommandText = "SELECT name FROM users WHERE user_id = @userId LIMIT 1";
    command.Parameters.AddWithValue("@userId", userId);
    return $"Hello, {await command.ExecuteScalarAsync()}";
});

app.MapGet("/products/{productId}", async (int productId, [FromKeyedServices("products")] MySqlConnection connection) =>
{
    await connection.OpenAsync();
    await using var command = connection.CreateCommand();
    command.CommandText = "SELECT name FROM products WHERE product_id = @productId LIMIT 1";
    command.Parameters.AddWithValue("@productId", productId);
    return await command.ExecuteScalarAsync();
});

If the service key is a string, it is also used as the default MySqlDataSource name.

8. Customize Keyed Data Source Names

To override the default name for a keyed data source, use the overload that accepts a MySqlDataSourceBuilder action and call UseName:

builder.Services.AddKeyedMySqlDataSource(
    "users",
    builder.Configuration.GetConnectionString("Users")!,
    dataSourceBuilder => dataSourceBuilder.UseName("UsersPool"));

The data source name is used by features such as metrics; see Metrics for more information.