SQL Server Entity Framework Core client integration

To get started with the Aspire SQL Server Entity Framework Core (EF Core) integration, install the 📦 Aspire.Microsoft.EntityFrameworkCore.SqlServer NuGet package in the client-consuming project, that is, the project for the application that uses the SQL Server EF Core client.

dotnet add package Aspire.Microsoft.EntityFrameworkCore.SqlServer

For an introduction to working with the SQL Server EF Core client integration, see Get started with the SQL Server EF Core integrations.

Add SQL Server database context

In the Program.cs file of your client-consuming project, call the AddSqlServerDbContext extension method on any IHostApplicationBuilder to register a Microsoft.EntityFrameworkCore.DbContext for use via the dependency injection container. The method takes a connection name parameter.

builder.AddSqlServerDbContext<ExampleDbContext>(connectionName: "database");

To retrieve ExampleDbContext object from a service:

public class ExampleService(ExampleDbContext context)
{
    // Use context...
}

For more information on dependency injection, see .NET dependency injection.

Properties of the SQL Server resources

When you use the WithReference method to pass a SQL Server server or database resource from the AppHost project to a consuming client project, several properties are available to use in the consuming project.

Aspire exposes each property as an environment variable named [RESOURCE]_[PROPERTY]. For instance, the Host property of a resource called sql becomes SQL_HOST.

SQL Server server resource

The SQL Server server resource exposes the following connection properties:

SQL Server database resource

The SQL Server database resource inherits all properties from its parent SqlServerServerResource and adds:

For example, if you reference a database resource named sqldb in your AppHost project, the following environment variables will be available in the consuming project:

• SQLDB_HOST
• SQLDB_PORT
• SQLDB_URI
• SQLDB_USERNAME
• SQLDB_PASSWORD
• SQLDB_DATABASENAME
• SQLDB_JDBCCONNECTIONSTRING

Enrich a SQL Server database context

You may prefer to use the standard EF Core method to obtain a database context and add it to the dependency injection container:

builder.Services.AddDbContext<ExampleDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("database")
        ?? throw new InvalidOperationException("Connection string 'database' not found.")));

You have more flexibility when you create the database context in this way, for example:

• You can reuse existing configuration code for the database context without rewriting it for Aspire.
• You can use EF Core interceptors to modify database operations.
• You can choose not to use EF Core context pooling, which may perform better in some circumstances.

If you use this method, you can enhance the database context with Aspire-style retries, health checks, logging, and telemetry features by calling the EnrichSqlServerDbContext method:

builder.EnrichSqlServerDbContext<ExampleDbContext>(
    configureSettings: settings =>
    {
        settings.DisableRetry = false;
        settings.CommandTimeout = 30; // seconds
    });

The settings parameter is an instance of the MicrosoftEntityFrameworkCoreSqlServerSettings class.

Configuration

The Aspire SQL Server Entity Framework Core integration provides multiple configuration approaches and options to meet the requirements and conventions of your project.

Use connection string

When using a connection string from the ConnectionStrings configuration section, you provide the name of the connection string when calling builder.AddSqlServerDbContext<TContext>():

builder.AddSqlServerDbContext<ExampleDbContext>("sql");

The connection string is retrieved from the ConnectionStrings configuration section:

{
  "ConnectionStrings": {
    "sql": "Data Source=myserver;Initial Catalog=master"
  }
}

The EnrichSqlServerDbContext won't make use of the ConnectionStrings configuration section since it expects a DbContext to be registered at the point it's called.

For more information, see the ConnectionString.

Use configuration providers

The Aspire SQL Server EF Core integration supports Microsoft.Extensions.Configuration. It loads the MicrosoftEntityFrameworkCoreSqlServerSettings from configuration files such as appsettings.json by using the Aspire:Microsoft:EntityFrameworkCore:SqlServer key. If you have set up your configurations in the Aspire:Microsoft:EntityFrameworkCore:SqlServer section you can just call the method without passing any parameter.

The following is an example of an appsettings.json file that configures some of the available options:

{
  "Aspire": {
    "Microsoft": {
      "EntityFrameworkCore": {
        "SqlServer": {
          "ConnectionString": "YOUR_CONNECTIONSTRING",
          "DbContextPooling": true,
          "DisableHealthChecks": true,
          "DisableTracing": true,
          "DisableMetrics": false
        }
      }
    }
  }
}

Use inline configurations

You can also pass the Action<MicrosoftEntityFrameworkCoreSqlServerSettings> delegate to set up some or all the options inline, for example to turn off the metrics:

builder.AddSqlServerDbContext<YourDbContext>(
    "sql",
    static settings =>
        settings.DisableMetrics = true);

Configure multiple DbContext connections

If you want to register more than one DbContext with different configuration, you can use $"Aspire.Microsoft.EntityFrameworkCore.SqlServer:{typeof(TContext).Name}" configuration section name. The json configuration would look like:

{
  "Aspire": {
    "Microsoft": {
      "EntityFrameworkCore": {
        "SqlServer": {
          "ConnectionString": "YOUR_CONNECTIONSTRING",
          "DbContextPooling": true,
          "DisableHealthChecks": true,
          "DisableTracing": true,
          "DisableMetrics": false
        },
        "AnotherDbContext": {
          "ConnectionString": "AnotherDbContext_CONNECTIONSTRING",
          "DisableTracing": false
        }
      }
    }
  }
}

Then calling the AddSqlServerDbContext method with AnotherDbContext type parameter would load the settings from Aspire:Microsoft:EntityFrameworkCore:SqlServer:AnotherDbContext section.

builder.AddSqlServerDbContext<AnotherDbContext>("another-sql");

Configuration options

Here are the configurable options with corresponding default values:

Health checks

By default, the Aspire Sql Server Entity Framework Core integration handles the following:

• Adds the DbContextHealthCheck, which calls EF Core's CanConnectAsync method. The name of the health check is the name of the TContext type.
• Integrates with the /health HTTP endpoint, which specifies all registered health checks must pass for app to be considered ready to accept traffic

Observability

Logging

The Aspire SQL Server Entity Framework Core integration uses the following Log categories:

• Microsoft.EntityFrameworkCore.ChangeTracking
• Microsoft.EntityFrameworkCore.Database.Command
• Microsoft.EntityFrameworkCore.Database.Connection
• Microsoft.EntityFrameworkCore.Database.Transaction
• Microsoft.EntityFrameworkCore.Infrastructure
• Microsoft.EntityFrameworkCore.Migrations
• Microsoft.EntityFrameworkCore.Model
• Microsoft.EntityFrameworkCore.Model.Validation
• Microsoft.EntityFrameworkCore.Query
• Microsoft.EntityFrameworkCore.Update

Tracing

The Aspire SQL Server Entity Framework Core integration will emit the following Tracing activities using OpenTelemetry:

• "OpenTelemetry.Instrumentation.EntityFrameworkCore"

Metrics

The Aspire SQL Server Entity Framework Core integration will emit the following metrics using OpenTelemetry:

• Microsoft.EntityFrameworkCore:
  • ec_Microsoft_EntityFrameworkCore_active_db_contexts
  • ec_Microsoft_EntityFrameworkCore_total_queries
  • ec_Microsoft_EntityFrameworkCore_queries_per_second
  • ec_Microsoft_EntityFrameworkCore_total_save_changes
  • ec_Microsoft_EntityFrameworkCore_save_changes_per_second
  • ec_Microsoft_EntityFrameworkCore_compiled_query_cache_hit_rate
  • ec_Microsoft_Entity_total_execution_strategy_operation_failures
  • ec_Microsoft_E_execution_strategy_operation_failures_per_second
  • ec_Microsoft_EntityFramew_total_optimistic_concurrency_failures
  • ec_Microsoft_EntityF_optimistic_concurrency_failures_per_second