Aspire.Npgsql.EntityFrameworkCore.PostgreSQL 8.0.0-preview.4.24156.9

Aspire.Npgsql.EntityFrameworkCore.PostgreSQL library

Registers EntityFrameworkCore DbContext in the DI container for connecting PostgreSQL®* database. Enables connection pooling, retries, health check, logging and telemetry.

Getting started

Prerequisites

• PostgreSQL database and connection string for accessing the database.

Install the package

Install the .NET Aspire PostgreSQL EntityFrameworkCore Npgsql library with NuGet:

dotnet add package Aspire.Npgsql.EntityFrameworkCore.PostgreSQL

Usage example

In the Program.cs file of your project, call the AddNpgsqlDbContext extension method to register a DbContext for use via the dependency injection container. The method takes a connection name parameter.

builder.AddNpgsqlDbContext<MyDbContext>("postgresdb");

You can then retrieve the MyDbContext instance using dependency injection. For example, to retrieve the context from a Web API controller:

private readonly MyDbContext _context;

public ProductsController(MyDbContext context)
{
    _context = context;
}

You might also need to configure specific option of Npgsql, or register a DbContext in other ways. In this case call the EnrichNpgsqlDbContext extension method, for example:

var connectionString = builder.Configuration.GetConnectionString("postgresdb");
builder.Services.AddDbContextPool<MyDbContext>(dbContextOptionsBuilder => dbContextOptionsBuilder.UseNpgsql(connectionString));
builder.EnrichNpgsqlDbContext<MyDbContext>();

Configuration

The .NET Aspire PostgreSQL EntityFrameworkCore Npgsql component provides multiple options to configure the database connection based on the requirements and conventions of your project.

Use a connection string

When using a connection string from the ConnectionStrings configuration section, you can provide the name of the connection string when calling builder.AddNpgsqlDbContext():

builder.AddNpgsqlDbContext<MyDbContext>("myConnection");

And then the connection string will be retrieved from the ConnectionStrings configuration section:

{
  "ConnectionStrings": {
    "myConnection": "Host=myserver;Database=test"
  }
}

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

See the ConnectionString documentation for more information on how to format this connection string.

Use configuration providers

The .NET Aspire PostgreSQL EntityFrameworkCore Npgsql component supports Microsoft.Extensions.Configuration. It loads the NpgsqlEntityFrameworkCorePostgreSQLSettings from configuration by using the Aspire:Npgsql:EntityFrameworkCore:PostgreSQL key. Example appsettings.json that configures some of the options:

{
  "Aspire": {
    "Npgsql": {
      "EntityFrameworkCore": {
        "PostgreSQL": {
          "HealthChecks": false,
          "Tracing": false
        }
      }
    }
  }
}

Use inline delegates

Also you can pass the Action<NpgsqlEntityFrameworkCorePostgreSQLSettings> configureSettings delegate to set up some or all the options inline, for example to disable health checks from code:

    builder.AddNpgsqlDbContext<MyDbContext>("postgresdb", settings => settings.HealthChecks = false);

or

    builder.EnrichNpgsqlDbContext<MyDbContext>(settings => settings.HealthChecks = false);

AppHost extensions

In your AppHost project, register a Postgres database and consume the connection using the following methods:

var postgresdb = builder.AddPostgres("pg").AddDatabase("postgresdb");

var myService = builder.AddProject<Projects.MyService>()
                       .WithReference(postgresdb);

The WithReference method configures a connection in the MyService project named postgresdb. In the Program.cs file of MyService, the database connection can be consumed using:

builder.AddNpgsqlDbContext<MyDbContext>("postgresdb");

Additional documentation

• https://learn.microsoft.com/ef/core/
• https://github.com/dotnet/aspire/tree/main/src/Components/README.md

Feedback & contributing

https://github.com/dotnet/aspire

*Postgres, PostgreSQL and the Slonik Logo are trademarks or registered trademarks of the PostgreSQL Community Association of Canada, and used with their permission.