# AspireEFPostgreSqlExtensions Methods

- Package: [Aspire.Npgsql.EntityFrameworkCore.PostgreSQL](/reference/api/csharp/aspire.npgsql.entityframeworkcore.postgresql.md)
- Type: [AspireEFPostgreSqlExtensions](/reference/api/csharp/aspire.npgsql.entityframeworkcore.postgresql/aspireefpostgresqlextensions.md)
- Kind: `Methods`
- Members: `2`

Provides extension methods for registering a PostgreSQL database context in an Aspire application.

## AddNpgsqlDbContext(IHostApplicationBuilder, string, Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>, Action<DbContextOptionsBuilder>)

- Name: `AddNpgsqlDbContext(IHostApplicationBuilder, string, Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>, Action<DbContextOptionsBuilder>)`
- Modifiers: `extension`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/cbc352350f1a9bafbaff10d14a2c8de4ac186a48/src/Components/Aspire.Npgsql.EntityFrameworkCore.PostgreSQL/AspireEFPostgreSqlExtensions.cs#L51-L100)

Registers the given `EntityFrameworkCore.DbContext` as a service in the services provided by the `builder`. Enables db context pooling, retries, corresponding health check, logging and telemetry.

```csharp
public static class AspireEFPostgreSqlExtensions
{
    public static void AddNpgsqlDbContext<TContext>(
        this IHostApplicationBuilder builder,
        string connectionName,
        Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>? configureSettings = null,
        Action<DbContextOptionsBuilder>? configureDbContextOptions = null)
    {
        // ...
    }
}
```

## Parameters

- `builder` (`IHostApplicationBuilder`)
  The `Hosting.IHostApplicationBuilder` to read config from and add services to.
- `connectionName` (`string`)
  A name used to retrieve the connection string from the ConnectionStrings configuration section.
- `configureSettings` (`Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>`) `optional`
  An optional delegate that can be used for customizing options. It's invoked after the settings are read from the configuration.
- `configureDbContextOptions` (`Action<DbContextOptionsBuilder>`) `optional`
  An optional delegate to configure the `EntityFrameworkCore.DbContextOptions` for the context.

## Exceptions

- `ArgumentNullException` -- Thrown if mandatory `builder` is null.
- `InvalidOperationException` -- Thrown when mandatory [NpgsqlEntityFrameworkCorePostgreSQLSettings.ConnectionString](/reference/api/csharp/aspire.npgsql.entityframeworkcore.postgresql/npgsqlentityframeworkcorepostgresqlsettings/properties.md#connectionstring) is not provided.

## Remarks

Reads the configuration from "Aspire:Npgsql:EntityFrameworkCore:PostgreSQL:{typeof(TContext).Name}" config section, or "Aspire:Npgsql:EntityFrameworkCore:PostgreSQL" if former does not exist.

The `DbContext.OnConfiguring` method can then be overridden to configure `EntityFrameworkCore.DbContext` options.

## EnrichNpgsqlDbContext(IHostApplicationBuilder, Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>)

- Name: `EnrichNpgsqlDbContext(IHostApplicationBuilder, Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>)`
- Modifiers: `extension`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/cbc352350f1a9bafbaff10d14a2c8de4ac186a48/src/Components/Aspire.Npgsql.EntityFrameworkCore.PostgreSQL/AspireEFPostgreSqlExtensions.cs#L112-L190)

Configures retries, health check, logging and telemetry for the `EntityFrameworkCore.DbContext`.

```csharp
public static class AspireEFPostgreSqlExtensions
{
    public static void EnrichNpgsqlDbContext<TContext>(
        this IHostApplicationBuilder builder,
        Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>? configureSettings = null)
    {
        // ...
    }
}
```

## Parameters

- `builder` (`IHostApplicationBuilder`)
- `configureSettings` (`Action<NpgsqlEntityFrameworkCorePostgreSQLSettings>`) `optional`

## Exceptions

- `ArgumentNullException` -- Thrown if mandatory `builder` is null.
- `InvalidOperationException` -- Thrown when mandatory `EntityFrameworkCore.DbContext` is not registered in DI.