Hi,

I've just run into the problem at the end of part 4. I'm getting the following error:

query GetSpeaker {
  speaker(id: 1) {
    name
  }
}

>>

{
  "errors": [
    {
      "message": "The ID `1` has an invalid format."
    }
  ]
}

My version of app is available here https://github.com/Sebosek/ConferencePlanner, probably I missing something.

The SpeakerQueries contains ID attribute with type int,

namespace ConferencePlanner.GraphQl.Speakers
{
    [ExtendObjectType(Name = Consts.QUERY)]
    public class SpeakerQueries
    {
        [UseApplicationDbContext]
        public Task<List<Speaker>> GetSpeakersAsync([ScopedService] ApplicationDbContext context) =>
            context.Speakers.ToListAsync();

        public Task<Speaker> GetSpeakerAsync(
            [ID(nameof(Speaker))] int id, 
            SpeakerByIdDataLoader dataLoader,
            CancellationToken cancellationToken) => dataLoader.LoadAsync(id, cancellationToken);
        
        public async Task<IReadOnlyCollection<Speaker>> GetSpeakersAsync(
            [ID(nameof(Speaker))] int[] ids, 
            SpeakerByIdDataLoader dataLoader,
            CancellationToken cancellationToken) => 
            await dataLoader.LoadAsync(ids, cancellationToken).ConfigureAwait(false);
    }
}

The SpeakerType contains ImplementationNode,

namespace ConferencePlanner.GraphQl.Types
{
    public class SpeakerType : ObjectType<Speaker>
    {
        protected override void Configure(IObjectTypeDescriptor<Speaker> descriptor)
        {
            descriptor
                .ImplementsNode()
                .IdField(p => p.Id)
                .ResolveNode(WithDataLoader);
            
            descriptor
                .Field(f => f.SessionSpeakers)
                .ResolveWith<SpeakerResolvers>(t => t.GetSessionsAsync(default!, default!, default!, default))
                .UseDbContext<ApplicationDbContext>()
                .Name("sessions");
        }

        private static Task<Speaker> WithDataLoader(IResolverContext context, int id) =>
            context.DataLoader<SpeakerByIdDataLoader>().LoadAsync(id, context.RequestAborted);
        
        private class SpeakerResolvers
        {
            public async Task<IReadOnlyCollection<Session>> GetSessionsAsync(
                Speaker speaker,
                [ScopedService] ApplicationDbContext dbContext,
                SessionByIdDataLoader sessionById,
                CancellationToken cancellationToken)
            {
                var ids = await dbContext.Speakers
                    .Where(w => w.Id == speaker.Id)
                    .Include(i => i.SessionSpeakers)
                    .SelectMany(s => s.SessionSpeakers.Select(e => e.SessionId))
                    .ToListAsync(cancellationToken)
                    .ConfigureAwait(false);

                return await sessionById.LoadAsync(ids, cancellationToken);
            }
        }
    }
}

And in ConfigureServices Relay is enabled

public void ConfigureServices(IServiceCollection services)
{
    services.AddSingleton(CreateAutomapper());
    services.AddPooledDbContextFactory<ApplicationDbContext>(options => 
        options.UseSqlite(CONNECTION_STRING).UseLoggerFactory(ApplicationDbContext.DbContextLoggerFactory));
    services
        .AddGraphQLServer()
        .AddQueryType(d => d.Name(Consts.QUERY))
            .AddTypeExtension<SpeakerQueries>()
            .AddTypeExtension<SessionQueries>()
            .AddTypeExtension<TrackQueries>()
        .AddMutationType(d => d.Name(Consts.MUTATION))
            .AddTypeExtension<SpeakerMutations>()
            .AddTypeExtension<SessionMutations>()
            .AddTypeExtension<TrackMutations>()
        .AddType<AttendeeType>()
        .AddType<SessionType>()
        .AddType<SpeakerType>()
        .AddType<TrackType>()
        .EnableRelaySupport()
        .AddDataLoader<SpeakerByIdDataLoader>()
        .AddDataLoader<SessionByIdDataLoader>();
}

Any idea, what should I check?

 public class SpeakerType : ObjectType<Speaker>
    {
        protected override void Configure(IObjectTypeDescriptor<Speaker> descriptor)
        {
            descriptor
                .Field(t => t.SessionSpeakers)
                .ResolveWith<SpeakerResolvers>(t => t.GetSessionsAsync(default!, default!, default!, default))
                .UseDbContext<ApplicationDbContext>()
                .Name("sessions");
        }

        private class SpeakerResolvers
        {
            public async Task<IEnumerable<Session>> GetSessionsAsync(
                Speaker speaker,
                ApplicationDbContext dbContext,
                SessionByIdDataLoader sessionById,
                CancellationToken cancellationToken)
            {
                int[] sessionIds = await dbContext.Speakers
                    .Where(s => s.Id == speaker.Id)
                    .Include(s => s.SessionSpeakers)
                    .SelectMany(s => s.SessionSpeakers.Select(t => t.SessionId))
                    .ToArrayAsync();

                return await sessionById.LoadAsync(sessionIds, cancellationToken);
            }
        }
    }

            builder.Services
              .AddGraphQLServer()
              .RegisterDbContext<ApplicationDbContext>(DbContextKind.Pooled)
              .AddQueryType<Query>()
              .AddMutationType<SpeakerMutation>()
              .AddType<SpeakerType>()
              .AddDataLoader<SpeakerByIdDataLoader>()
              .AddDataLoader<SessionByIdDataLoader>();

I've updated the speaker model, added the speakerType, ran the migration and updated the database, however the schema in the browser still does not show the SessionSpeakers collection.

Has there been any changes between the versions?

After upgrading Session #6's HotChocolate.AspNetCore and HotChocolate.Data to version 12.4.1 running

query GetSessionsContaining2InTitle {
  sessions(where: { title: { contains: "2" } }) {
    nodes {
      title
    }
  }
}

gives error

{
"errors": [
 {
   "message": "Unexpected Execution Error",
   "locations": [
     {
       "line": 2,
       "column": 3
     }
   ],
   "path": [
     "sessions"
   ],
   "extensions": {
     "message": "Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.\r\nObject name: 'ApplicationDbContext'.",
     "stackTrace": "   at Microsoft.EntityFrameworkCore.DbContext.CheckDisposed()\r\n   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()\r\n   at Microsoft.EntityFrameworkCore.DbContext.get_Model()\r\n   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()\r\n   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.CheckState()\r\n   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()\r\n   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()\r\n   at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate)\r\n   at HotChocolate.Data.Filters.Expressions.QueryableFilterProvider.<>c__DisplayClass11_0`1.<CreateApplicatorAsync>b__0(IResolverContext context, Object input)\r\n   at HotChocolate.Data.Filters.Expressions.QueryableFilterProvider.<>c__DisplayClass10_0`1.<<CreateExecutor>g__ExecuteAsync|1>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at HotChocolate.Types.Pagination.PagingMiddleware.InvokeAsync(IMiddlewareContext context)\r\n   at HotChocolate.Utilities.MiddlewareCompiler`1.ExpressionHelper.AwaitTaskHelper(Task task)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.ExecuteResolverPipelineAsync(CancellationToken cancellationToken)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.TryExecuteAsync(CancellationToken cancellationToken)"
   }
 }
],
"data": {
 "sessions": null
}
}

But, removing disposeAsync: (s, c) => c.DisposeAsync() argument from descriptor.UseScopedService in ObjectFieldDescriptorExtensions class's UseDbContext method resolved the error.

public static class ObjectFieldDescriptorExtensions
 {
     public static IObjectFieldDescriptor UseDbContext<TDbContext>(
         this IObjectFieldDescriptor descriptor)
         where TDbContext : DbContext
     {
         return descriptor.UseScopedService<TDbContext>(
             create: s => s.GetRequiredService<IDbContextFactory<TDbContext>>().CreateDbContext());
     }

     public static IObjectFieldDescriptor UseUpperCase(
         this IObjectFieldDescriptor descriptor)
     {
         return descriptor.Use(next => async context =>
         {
             await next(context);

             if (context.Result is string s)
             {
                 context.Result = s.ToUpperInvariant();
             }
         });
     }
 }

So, my question is that Is explicitly adding disposeAsync attribute necessary for disposing of the DbContext?

I'm trying to write my QueryType using ObjectType and IObjectTypeDescriptor,

My Id field are Guid types, the following code output 2 queries, the 1st one works fine. the 2nd one does not.

descriptor
.Field($"sessionById")
.Argument("id", a => a.ID().Type(typeof(Guid))) // add Input Argument
.UseDbContext()
.ResolverWith(r=> ...);

descriptor
.Field($"sessionListById")
.Argument("ids", a => a.ID().Type(typeof(Guid[]))) // add Input Argument
.UseDbContext()
.ResolverWith(r=> ...);

I have 2 problems:
Problem 1:
The argument for the 2nd query will be output to : ids: [ID!] , instead of ids: [ID!]! --- should be not null field.

Problem 2:
when I plug my ID value into the 2nd query input, I got the following error telling me the IDs have an invalid format.

The same ID works for the first query when input just uses single ID instead of an Array.

query GetSessions {
a: sessionListById(ids: ["U2Vzc2lvbgpnNWUxZmEzNWU3YWFiNGZkMmI0ZWM5YTM1YjE1OTY1NjQ="])
{
id,
title
}
b: sessionById(id: "U2Vzc2lvbgpnNWUxZmEzNWU3YWFiNGZkMmI0ZWM5YTM1YjE1OTY1NjQ=")
{
id,
title
}
}

Result:
{
"errors": [
{
"message": "The IDs U2Vzc2lvbgpnNWUxZmEzNWU3YWFiNGZkMmI0ZWM5YTM1YjE1OTY1NjQ= have an invalid format."
}
],
"data": {
"a": null,
"b": {
"id": "U2Vzc2lvbgpnNWUxZmEzNWU3YWFiNGZkMmI0ZWM5YTM1YjE1OTY1NjQ=",
"title": "Session 5"
}
}
}

Anyone can help?

The class SessionAttendeeCheckIn currently have two definitions of GetAttendeeAsync

But it seems to me that the latter should be GetSessionAsync instead. Or am I missing something?

That part is specifically covered in 7-subscriptions.
... # 2 in https://github.com/ChilliCream/graphql-workshop/blob/master/docs/7-subscriptions.md#add-onattendeecheckedin-subscription

I'll be happy to create a PR if it needs correction

Btw, thank you for creating this workshop. I'm learning graphql and I'm having a great learning experience so far.

In Session 3 found

Important: Note, that we no longer are returning the IQueryable but are executing the IQueryable by using ToListAsync. We will explain why later in the middleware and filter session.

But where to find it explanation? In Session 5 something about middleware, but in 6-th there is... IQueryable, again! How this magic works?

[UseApplicationDbContext]
[UsePaging]
public IQueryable<Track> GetTracks(
    [ScopedService] ApplicationDbContext context) =>
    context.Tracks.OrderBy(t => t.Name);

I've tried in my project:

[UsePersonDbContext]
[UseProjection]
public IQueryable<EducactionLevel> GetEducactionLevels(
    [ScopedService] PersonDbContext context)
{
    return context.EducactionLevels;
}

where PersonDbContext is registered by services.AddPooledDbContextFactory<PersonDbContext>(...), but got

Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'PersonDbContext'.

So question is:

• How to use projections with PooledDbContextFactory?

How to use projection in data loader

Hello,

I'm following the tutorial and during step 4 in the part that adds relay support to the schema I'm getting the error The ID 1 has an invalid format.

I tried with the provided code but got the same error.

My query is:

{
  node (id: "1") {
    id
    ... on Speaker {
      bio
    }
  }
}

and

{
  speaker (id: 1) {
    bio
  }
}

I'm currently trying to figure out how to add a unit test for subscription. :)

References:
https://github.com/ChilliCream/graphql-workshop/blob/master/docs/8-testing-the-graphql-server.md
https://chillicream.com/docs/hotchocolate/api-reference/aspnetcore#subscription-session-handling

Hi,

I cannot figure how to get the schema as graphql or json with 11.0.0.rc2 or rc4.
Neither http://localhost:5000/schema or http://localhost:5000/graphql/schema works.
I read a lot of threads in slack but in vain.

Could you add a section explaining this point ?
For now, I use npm package get-graphql-schema to provide it to my client.

Best,

On my solution, As soon as I apply the logic to allow parallel query, I get the following exception:
Unable to resolve service for type 'DAL.PRdbContext' while attempting to activate 'DAL.Repositories.UserRepository'

For more details on my project architecture, please visit the post I created on Stackoverflow.

Hello, I'm trying to complete the third part of this tutorial and I can't get past the definition of more types. Everything works well till the "Enable Relay support" section. But when I try to add more data loaders and schema types, my program crashes with this error message:

"An unhandled exception of type 'HotChocolate.SchemaException' occurred in System.Private.CoreLib.dll
The name Mutation was already registered by another type. - Type: Mutation"

I tried to rewrite it twice, to find the source of the error, but I didn't come up with anything. I would be grateful if there was someone who could look at it. Here is my project repository.

The updated "complete" sample code shows using v12. However, when I get the following error after adding the dataloader classes in step 3.

{
  "errors": [
    {
      "message": "There was no argument with the name `speaker` found on the field `sessions`.",
      "locations": [
        {
          "line": 4,
          "column": 5
        }
      ],
      "path": [
        "speakers",
        0,
        "sessions"
      ],
      "extensions": {
        "fieldName": "sessions",
        "argumentName": "speaker"
      }
    }
  ]
}

3-understanding-dataLoader.md, section Fluent type configurations, Step 4. - Description says to add SessionType class. Code example shows SpeakerType instead. I think SessionType should be SpeakerType. Step 7. Query should be for speakers instead of speaker since no id is provided

Problem:
In some machines you can have problem to use ef because of dotnet-tools.json was created on different machine.. And is included in project... Windows use location timestamp

Location:
https://github.com/ChilliCream/graphql-workshop/tree/master/code/complete/.config (and all others)

Error

File  ..../graphql-workshop-master\graphql-workshop-master\code\complete\.config\dotnet-tools.json came from another computer and might be blocked to help protect this computer. For more information, including how to unblock, see https://aka.ms/motw

Removing of course solve the problem..

Recommendation
Moving all this .config folders to .gitignore (not needed to update database)... If needed and people follow workshop tools will be installed from it...

From page 3 this extension and attribute are asked to be made. It seems these are in the Types and Data namespace in newer versions of HC? Are they the same or is this a bit outdated?

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using HotChocolate.Types;

namespace ConferencePlanner.GraphQL
{
    public static class ObjectFieldDescriptorExtensions
    {
        public static IObjectFieldDescriptor UseDbContext<TDbContext>(
            this IObjectFieldDescriptor descriptor)
            where TDbContext : DbContext
        {
            return descriptor.UseScopedService<TDbContext>(
                create: s => s.GetRequiredService<IDbContextFactory<TDbContext>>().CreateDbContext(),
                disposeAsync: (s, c) => c.DisposeAsync());
        }
    }
}
The UseDbContext will create a new middleware that handles scoping for a field. The create part will rent from the pool a DBContext, the dispose part will return it after the middleware is finished. All of this is handled transparently through the new IDbContextFactory<T> introduced with .NET 5.

Create another file located in Extensions called UseApplicationDbContextAttribute.cs with the following code:

using System.Reflection;
using ConferencePlanner.GraphQL.Data;
using HotChocolate.Types;
using HotChocolate.Types.Descriptors;

namespace ConferencePlanner.GraphQL
{
    public class UseApplicationDbContextAttribute : ObjectFieldDescriptorAttribute
    {
        public override void OnConfigure(
            IDescriptorContext context,
            IObjectFieldDescriptor descriptor,
            MemberInfo member)
        {
            descriptor.UseDbContext<ApplicationDbContext>();
        }
    }
}```

Noticed it first in session 4:

But checked sessons 5,6,7 and 8 and it's GetSessionsByIdAsync in there as well.

EROR always when need return null.

Calling await sender.SendAsync($"CaseInProgress_{runId}", (int?)null);

public class CaseInProgressChangedPayload
  {
    public int? CaseInProgress { get; set; }
  }

  [Subscribe]
  [Topic("CaseInProgress_{runId}")]
  public CaseInProgressChangedPayload OnCaseInProgressChanged(int runId, [EventMessage] int? caseInProgress)
  {
    return new CaseInProgressChangedPayload
    {
      CaseInProgress = caseInProgress
    };
  }

OR
[Subscribe]
  [Topic("CaseInProgress_{runId}")]
  public int? OnCaseInProgressChanged(int runId, [EventMessage] int? caseInProgress) => caseInProgress;

OR
[Subscribe]
  [Topic("CaseInProgress_{runId}")]
  public int? OnCaseInProgressChanged(int runId, [EventMessage] int? caseInProgress)
  {
    return caseInProgress;
  }

Full log:
{"type":"connection_ack"}
{
"id": "91f6db40-c442-45d3-b0d3-bf792ed379ee",
"type": "error",
"payload": [
{
"message": "Value cannot be null. (Parameter 'payload')",
"extensions": {
"message": "Value cannot be null. (Parameter 'payload')",
"stackTrace": " at HotChocolate.Execution.Instrumentation.SubscriptionEventContext..ctor(ISubscription subscription, Object payload)\r\n at HotChocolate.Execution.Processing.SubscriptionExecutor.Subscription.OnEvent(Object payload)\r\n at HotChocolate.Execution.Processing.SubscriptionExecutor.SubscriptionEnumerator.MoveNextAsync()\r\n at HotChocolate.AspNetCore.Subscriptions.OperationSession.SendResultsAsync(GraphQLRequest request, CancellationToken cancellationToken)\r\n at HotChocolate.AspNetCore.Subscriptions.OperationSession.SendResultsAsync(GraphQLRequest request, CancellationToken cancellationToken)\r\n at HotChocolate.AspNetCore.Subscriptions.OperationSession.SendResultsAsync(GraphQLRequest request, CancellationToken cancellationToken)"
}
}
]
}

Hi. I noticed that data annotations like [StringLength(100)] or [MinLength(10), MaxLength(20)] have no effect on generated database. For example Data/Speaker class from Session 6 looks in SQL like this:

CREATE TABLE "Speakers" (
    "Id" INTEGER NOT NULL CONSTRAINT "PK_Speakers" PRIMARY KEY AUTOINCREMENT,
    "Name" TEXT NOT NULL,
    "Bio" TEXT NULL,
    "WebSite" TEXT NULL)

Is this correct behaviour?

In 4-schema-design, AddTypeExtension and AddType is used interchangeably. I'm curious as well as confused because of this. I'll probably be able to clarify this later when I get to learn more about graphql and hc. But any response will be greatly appreciated.

e.g.

14. Head back to the Startup.cs and add the TrackMutations to the schema builder.

  services
      .AddGraphQLServer()
      .AddQueryType(d => d.Name("Query"))
          .AddTypeExtension<SpeakerQueries>()
      .AddMutationType(d => d.Name("Mutation"))
          .AddTypeExtension<SessionMutations>()
          .AddTypeExtension<SpeakerMutations>()
          .AddTypeExtension<TrackMutations>()
      .AddType<AttendeeType>()
      .AddType<SessionType>()
      .AddType<SpeakerType>()
      .AddType<TrackType>()
      .EnableRelaySupport()
      .AddDataLoader<SpeakerByIdDataLoader>()
      .AddDataLoader<SessionByIdDataLoader>();

6. Again, head over to the Startup.cs and register the TrackQueries with the schema builder.

   services
        .AddGraphQLServer()
        .AddQueryType(d => d.Name("Query"))
            .AddType<SessionQueries>()
            .AddType<SpeakerQueries>()
            .AddType<TrackQueries>()
        .AddMutationType(d => d.Name("Mutation"))
            .AddType<SessionMutations>()
            .AddType<SpeakerMutations>()
            .AddType<TrackMutations>()
        .AddType<AttendeeType>()
        .AddType<SessionType>()
        .AddType<SpeakerType>()
        .AddType<TrackType>()
        .EnableRelaySupport();

Hi. I started with new version of tutorials and get stuck in first session. I downloaded Session 1, builded project, generated DB and tried to fetch some data over Banana Cake Pop which ended up with error

 {
  "name": "ServerNetworkError",
  "statusText": "Failed to fetch"
}

Then I tried to install playground and run it in browser. Same issue.

Do anyone have the same problem or is it just on my side?

EDIT: Sessions 2 and 6 both have the same problem.
EDIT2: Problem is that HTTPS port 5001 cannot be accessed. HTTP 5000 works fine.

Session # 2 demonstrates how HC leverages C#'s nullable reference types.
In Session # 6 NonNullType is used...

.ResolveWith<TrackResolvers>(t => t.GetSessionsAsync(default!, default!, default))
.UsePaging<NonNullType<SessionType>>()

...but it looks like it doesn't affect the generated schema at all.

The graphql type nullability is controlled by nullable reference types:

• Task<IEnumerable<Session>> GetSessionsAsync for non-nullable Session
• Task<IEnumerable<Session?>> GetSessionsAsync for nullable Sessions

Is it ok to remove the use of NonNullType if nullable reference types is enabled?

Hi! I want to try the get started found here: https://chillicream.com/docs/strawberryshake/get-started and the following project is generated. I found that the RenameSession is not work correctly after click the Save button. The problem occurred in the graphql server .

The error msg as follows:
https://files.slack.com/files-pri/TD98NH6TS-F02RX8AQ5FZ/image.png
https://files.slack.com/files-pri/TD98NH6TS-F02RVR6BTEK/image.png

And the function should be modified as follows:

[UseApplicationDbContext]
    public async Task<RenameSessionPayload> RenameSessionAsync(
        RenameSessionInput input,
        [ScopedService] ApplicationDbContext context,
        [Service]ITopicEventSender eventSender)
    {
        var session = await context.Sessions.FindAsync( int.Parse( input.SessionId));

        if (session is null)
        {
            return new RenameSessionPayload(
                new UserError("Session not found.", "SESSION_NOT_FOUND"));
        }

        session.Title = input.Title;

        await context.SaveChangesAsync();

        await eventSender.SendAsync(
            nameof(SessionSubscriptions.OnSessionScheduledAsync),
            session.Id);

        return new RenameSessionPayload(session);
    }

The graphql-workshop provided me a very detailed introduction to HotChocolate features. All features and code worked correctly with V11.
However, after I ungraded HotChocolate libraries to V12.9.0, I hit the following exception during query execution:
Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.\r\nObject name: 'ApplicationDbContext'.

After reading through your detailed V12 documentation here:
https://chillicream.com/docs/hotchocolate/integrations/entity-framework.
I suspect the issue must be related to enhanced disposeasync logic in V12. The query executions worked fine again after I commented the manual disposeAsync logic as shown here.

    public static IObjectFieldDescriptor UseDbContext<TDbContext>(
        this IObjectFieldDescriptor descriptor)
        where TDbContext : DbContext
    {
        return descriptor.UseScopedService<TDbContext>(
            create: s => s.GetRequiredService<IDbContextFactory<TDbContext>>().CreateDbContext());
        //return descriptor.UseScopedService<TDbContext>(
        //    create: s => s.GetRequiredService<IDbContextFactory<TDbContext>>().CreateDbContext(),
        //    disposeAsync: (s, c) => c.DisposeAsync());
    }

If possible it would help to include V12 and V13 enhanced features into your excellent workshop sample. I plan to implement HotChocolate V12 for my future projects. Thank you.

Executing the last query GetSpeakerWithSessions on session 3 I have the following error:

{
  "errors": [
    {
      "message": "There was no argument with the name `speaker` found on the field `sessions`.",
      "locations": [
        {
          "line": 4,
          "column": 8
        }
      ],
      "path": [
        "speakers",
        0,
        "sessions"
      ],
      "extensions": {
        "fieldName": "sessions",
        "argumentName": "speaker"
      }
    }
  ]
}

I'm following the workshop trying to implement all the flow using ASP.NET Core 6 and HotChocolate version 12.7.0.
Source code is available here: https://github.com/albx/graphql-workshop/tree/part-3

Am I missing something?
Thank you very much for your help!

version 12.0.1
In the Fluent Type configuration section, step 4 of 3-understanding-dataloader.md, the code

   private class SpeakerResolvers
        {
            public async Task<IEnumerable<Session>> GetSessionsAsync(
                Speaker speaker,
                [ScopedService] ApplicationDbContext dbContext,
                SessionByIdDataLoader sessionById,
                CancellationToken cancellationToken)
            {
                int[] sessionIds = await dbContext.Speakers
                    .Where(s => s.Id == speaker.Id)
                    .Include(s => s.SessionSpeakers)
                    .SelectMany(s => s.SessionSpeakers.Select(t => t.SessionId))
                    .ToArrayAsync();

                return await sessionById.LoadAsync(sessionIds, cancellationToken);
            }
        }

throws the error :

There was no argument with the name speaker found on the field `sessions

If the Speaker parameter is annotated with [Parent] then everything works. I have not verified it but I assume that the SessionResolvers and AttendeeResolvers defined in 4-schema-design.md have the same issue.

The section in the user guide regarding arguments for resolvers is really sketchy. It would be very helpful if the paragraph

There are also specific arguments that will be automatically populated by Hot Chocolate when the resolver is executed. These include Dependency injection services, DataLoaders, state, or even context like a parent value.

was elaborated. From what is written I understand that any registered service can be injected but I have no idea what is meant by

state, or even context like a parent value

Following the docs until the explanation of [Fluent Type Configurations on page 3-understanding-dataLoader.md] (https://github.com/ChilliCream/graphql-workshop/blob/master/docs/3-understanding-dataLoader.md#fluent-type-configurations).
Executing query

query GetSpeakerWithSessions { speakers { name sessions { title } } }

Should produce list of speakers with empty sessions list
Produces instead "There was no argument with the name speaker found on the field sessions." for each speaker on line 4 column 5 of the query.

In Session 6 it talks about adding pagination and demonstrates that with a query for tracks to include paginated sessions.

Unfortunately at that point int he workshop there is no way to add a track and associate or schedule sessions to it.

I think the mutation comes later on but without it the dev gets an error. Also would it be possible to include some example queries to cut and paste to help populate the DB to be able to follow the workshop?

Caching is not working, actually not returning any data from query, but if I close .UseQueryCachePipeline() I can see the data when queriying.

It adds the Cache Control header but not returning any value

I published the code to public github: https://github.com/baytekink/GraphQL you can download and start directly to test

Hi @Sebosek
Can you please more explain this problem and give some code how should look like that part.

thanks

Originally posted by @davorinjurkovic007 in #39 (comment)

I have been battling with the Track queries with pagination in Session 6 for several hours without success. Later I got to realize that the Field descriptor for Sessions needed to be provided with "UseDbContext" middleware in the TrackType.

However the tutorials lack that middleware, is it an error or I was not doing it right.

I'm trying to understand why creating a separate UseApplicationDbContextAttribute (and the IObjectFieldDescriptor extension) would be necessary at all (steps 5+6 and usage later). I've been loosely following the examples and could not force/reproduce the parallel execution error. Digging into the sources, I found that the default UseDbContext attribute that's coming with the EntityFramework package forwards to a built-in extension method for IObjectFieldDescriptor that's basically already doing the same thing like the manually implemented logic in session 3, doesn't it?

Am I correct that this separate implementation on the application level is not necessary anymore?

i have a 1:M relationship an need nested query

Example

i have one table client with id 1

and table sales with any sales data with client id 1

my result in playground

"data": { "cliente": { "nOMBRE": "juanito", "ventasByRut": [ null, null, null ] } } }

code:

` public async Task<IEnumerable> GetVentasAsync(
Cliente cliente,
[ScopedService] DataContext dataContext,
VentaByIdDataLoader ventaById,
CancellationToken cancellationToken)
{
int[] ventaIds = await dataContext.VENTA
.Where(s => s.CLIENTERUT == cliente.RUT)
.Select(s => s.CLIENTERUT)
.ToArrayAsync();

            return await ventaById.LoadAsync(ventaIds, cancellationToken);
                
        }`

console SQL log :

info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (162ms) [Parameters=[], CommandType='Text', CommandTimeout='0']
SELECT "c"."RUT", "c"."NOMBRE"
FROM "CLIENTE" "c"
WHERE ("c"."RUT" = 12333444)
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (41ms) [Parameters=[:cliente_RUT_0='12333444'], CommandType='Text', CommandTimeout='0']
SELECT "v"."CLIENTERUT"
FROM "VENTA" "v"
WHERE ("v"."CLIENTERUT" = :cliente_RUT_0)
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (1ms) [Parameters=[], CommandType='Text', CommandTimeout='0']
SELECT "v"."IDVENTA", "v"."CANTIDAD", "v"."CLIENTERUT", "v"."MONTO", "v"."PRECIO"
FROM "VENTA" "v"
WHERE ("v"."IDVENTA" = 12333444)

Hello guys...
I have completed the session 1.
Accessing http://localhost:5000/graphql/ in browser always get this...

AddSpeaker Mutation doesn't show up in the client tool in the Conference Planner tutorial. I can't access the standalone client so I'm using the middleware test page.

I would suggest not teaching people to setup the project incorrectly but go directly to setting up correctly with attribute that supports the middleware. Maybe in passing mention the wrong way to set it up but no need to go through all the details. Most people will just follow what you suggest.

That is, explain the setup in the first chapter, then have the dataloader discussion just be about dataloader.

Please update graphql workshop on basis latest version

As per GraphQL-Workshop and Session #3 Understanding GraphQL query execution and DataLoader

I followed Steps 3, 4, 5, 6 & 7 and everything worked as expected.
But Warning is shown while using [ScopedService] that it is Obsolete and I should use [Service(ServiceKind.Pooled)] or [Service(ServiceKind.Resolver)].
But when I use either [Service(ServiceKind.Pooled)] or [Service(ServiceKind.Resolver)] then getting error as following.

"No service for type 'Microsoft.Extensions.ObjectPool.ObjectPool`1[ApplicationDbContext]' has been registered."

I'm trying to configure Identity with HotChocolate, but just cannot get it to work? Sincerely help.

Microsoft.AspNetCore.Identity

Hi,
Couldn't find anything on schema stiching. Will any new episode on this be added recently?
Thanks

Full error:

{
"errors": [
{
"message": "The field id does not exist on the type CommandsConnection.",
"locations": [
{
"line": 59,
"column": 9
}
],
"path": [
"addCommandsIdentifier",
"commandsIdentifier",
"commands"
],
"extensions": {
"type": "CommandsConnection",
"field": "id",
"responseName": "id",
"specifiedBy": "http://spec.graphql.org/October2021/#sec-Field-Selections-on-Objects-Interfaces-and-Unions-Types"
}
},
{
"message": "The field content does not exist on the type CommandsConnection.",
"locations": [
{
"line": 60,
"column": 9
}
],
"path": [
"addCommandsIdentifier",
"commandsIdentifier",
"commands"
],
"extensions": {
"type": "CommandsConnection",
"field": "content",
"responseName": "content",
"specifiedBy": "http://spec.graphql.org/October2021/#sec-Field-Selections-on-Objects-Interfaces-and-Unions-Types"
}
}
]
}

the type:

`
protected override void Configure(IObjectTypeDescriptor descriptor)
{
descriptor
.ImplementsNode()
.IdField(t => t.Id)
.ResolveNode((ctx, id) => ctx.DataLoader().LoadAsync(id, ctx.RequestAborted));

        descriptor
            .Field(t => t.Commands)
            .ResolveWith<CommandResolvers>(t => t.GetCommandsAsync(default!, default!, default!, default))
            .UseDbContext<ApplicationDbContext>()
            .UsePaging<NonNullType<CommandType>>()
            .Name("commands");
    }

`

and the query:

public class CommandQueries { [UseApplicationDbContext] [UsePaging(typeof(NonNullType<CommandType>))] public IQueryable<Command> GetCommands([ScopedService] ApplicationDbContext context) => context.Commands; }

I am following the workshop and I see that since the introduction of recommending to use HotChocolate.AspNetCore 11.0.0-rc.0 it introduced breaking changes for the Schema Explorer in Banana Cake Pop.

At first I believed I did something wrong, but I went on and downloaded the source code of this repository to check if the completed session 1 code is also breaking, and it is. I went through the commits of this repository to find the session 1 with the "old" API of version 10.5.X. and that worked.

I am not sure what the problems is, but I know that it is breaking here:

The "old" API uses the following syntax that works:

In this section:
https://github.com/ChilliCream/graphql-workshop/blob/master/docs/1-creating-a-graphql-server-project.md#adding-mutations

Relay mutation pattern link gives 404 Not Found:
relay mutation pattern

Adding mutation in Startup.cs

services .AddGraphQLServer() .AddQueryType<Query>() .AddMutationType<Mutation>();

and the playground don't show in the schema.

why dont show in the playground?

i need restart navigator? any simple solution?

All ToArrayAsync do not use cancelation tokens

The ID is stored as a Guid in my database, but when queried through GraphQL, it is returned as a base64 encoded string.
i am facing this problem after enabling relay policy and implementing the reolver to improve data fetch. Is there a way to configure a custom serializer or scalar type for Guid values in the schema?

When completing section 3 "Understanding Dataloaders", with the introduction of SpeakerType, and SpeakerResolvers, I'm getting the error:

{
  "errors": [
    {
      "message": "There was no argument with the name `speaker` found on the field `sessions`.",
      "locations": [
        {
          "line": 5,
          "column": 6
        }
      ],
      "path": [
        "speakers",
        0,
        "sessions"
      ],
      "extensions": {
        "fieldName": "sessions",
        "argumentName": "speaker"
      }
    }
  ]
}