Dependency Injection | SurrealDB Docs

The SurrealDB SDK for .NET also supports the concept of Dependency Injection pattern.

The .NET SDK also support Dependency Injection to ease the use of SurrealDbClient and SurrealDbSession in your application.

Create a new project

Let's start by creating a new ASP.NET Core web app.

dotnet new webapp -o SurrealDbWeatherApi
cd SurrealDbWeatherApi
dotnet add package SurrealDb.Net

Define a connection string

Open appsettings.Development.json and replace everything in there with the following code. We have added a new Connection String called SurrealDB with the default configuration.

{
  "AllowedHosts": "*",
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "ConnectionStrings": {
    "SurrealDB": "Server=http://127.0.0.1:8000;Namespace=test;Database=test;Username=root;Password=root"
  }
}

Register services

Open Program.cs and replace everything in there with the following code. This code is using the AddSurreal() extension method to inject services automatically. Notice that all we have to do is one line of code to configure the SurrealDB client with the previously set Connection String.

Note

By default, this function will register both ISurrealDbSession and SurrealDbSession using the Scoped service lifetime. This mean that a new isolated SurrealDB session is created per scope.

var builder = WebApplication.CreateBuilder(args);

var services = builder.Services;
var configuration = builder.Configuration;

services.AddControllers();
services.AddEndpointsApiExplorer();
services.AddSwaggerGen();
services.AddSurreal(configuration.GetConnectionString("SurrealDB"));

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseAuthorization();

app.MapControllers();

app.Run();

Note

In this example, we use a Connection String to configure services. This is the most convenient way to initialize the SurrealDbClient in your application. You can always choose to construct a Connection String manually via a SurrealDbOptionsBuilder and pass it to the AddSurreal() method.

Consume the SurrealDB client/session

Open WeatherForecastController.cs and replace everything in there with the following code. Finally, we can inject the SurrealDbSession inside our Controller.

using Microsoft.AspNetCore.Mvc;

namespace SurrealDbWeatherApi.Controllers;

[ApiController]
[Route("[controller]")]
public class WeatherForecastController : ControllerBase
{
    private const string Table = "weatherForecast";

    private readonly SurrealDbSession _db;

    public WeatherForecastController(SurrealDbSession db)
    {
        _db = db;
    }

    [HttpGet]
    [Route("/")]
    public Task<List<WeatherForecast>> GetAll(CancellationToken cancellationToken)
    {
        return _db.Select<WeatherForecast>(Table, cancellationToken);
    }

    [HttpPost]
    [Route("/")]
    public Task<WeatherForecast> Create(CreateWeatherForecast data, CancellationToken cancellationToken)
    {
        var weatherForecast = new WeatherForecast
        {
            Date = data.Date,
            Country = data.Country,
            TemperatureC = data.TemperatureC,
            Summary = data.Summary
        };

        return _db.Create(Table, weatherForecast, cancellationToken);
    }

    // ...
    // Other methods omitted for brevity
}

public class CreateWeatherForecast
{
    public DateTime Date { get; set; }
    public string? Country { get; set; }
    public int TemperatureC { get; set; }
    public string? Summary { get; set; }
}

Then make sure your SurrealDB server is running on 127.0.0.1:8000 and run your app from the command line with:

dotnet run