Code Using GraphQL

using System;
using System.Threading.Tasks;
using GraphQL;
using GraphQL.Types;
using GraphQL.SystemTextJson; // First add PackageReference to GraphQL.SystemTextJson
 
public class Program
{
  public static async Task Main(string[] args)
  {
    var schema = Schema.For(@"
      type Query {
        hello: String
      }
    ");
 
    var json = await schema.ExecuteAsync(_ =>
    {
      _.Query = "{ hello }";
      _.Root = new { Hello = "Hello World!" };
    });
 
    Console.WriteLine(json);
  }
}

client.GetHero
    .Watch(ExecutionStrategy.CacheFirst)
    .Subscribe(result =>
    {
        Console.WriteLine(result.Data.Name);
    })

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
 
WebHost
    .CreateDefaultBuilder(args)
    .ConfigureServices(services =>
        services
            .AddGraphQLServer()
            .AddQueryType<Query>())
    .Configure(builder =>
        builder
            .UseRouting()
            .UseEndpoints(e => e.MapGraphQL()))
    .Build()
    .Run();
 
public class Query
{
    public Hero GetHero() => new Hero();
}
 
public class Hero
{
    public string Name => "Luke Skywalker";
}

// expose an exisiting data model with ASP.NET & EF Core
public class Startup {
  public void ConfigureServices(IServiceCollection services)
  {
      services.AddDbContext<DemoContext>();
      // Auto build a schema from DemoContext. Alternatively you can build one from scratch
      services.AddGraphQLSchema<DemoContext>(options =>
      {
          // modify the schema (add/remove fields or types), add other services
      });
  }
 
  public void Configure(IApplicationBuilder app, DemoContext db)
  {
      app.UseRouting();
      app.UseEndpoints(endpoints =>
      {
          // defaults to /graphql endpoint
          endpoints.MapGraphQL<DemoContext>();
      });
  }
}

var userId = 10;
var response = await qlClient.Query(q => q
    .User(userId, o => new
    {
        o.Id,
        o.FirstName,
        o.LastName
    }));