C#•9mo ago

System.InvalidOperationException: The LINQ expression 'DbSet<WorkingTask>() .Where(w => new Work

I have following code:

[UsePaging]
    [UseProjection]
    [UseFiltering]
    [UseSorting]
    [Authorize(Roles = [Permissions.Rms.Task.Read])]
    public IQueryable<WorkingTask> WorkingTasks([Service(ServiceKind.Resolver)] ReadModelDbContext dbContext, IResolverContext context, [Service] NpgsqlHealthChecker npgsqlHealthChecker)
    {
        var workingTasks = dbContext.WorkingTasks
            .AsQueryable()
            .Project(context)
            .Filter(context)
            .Sort(context)
            .ToList(); // Force client-side evaluation

        return workingTasks.AsQueryable();
    }

[UsePaging]
    [UseProjection]
    [UseFiltering]
    [UseSorting]
    [Authorize(Roles = [Permissions.Rms.Task.Read])]
    public IQueryable<WorkingTask> WorkingTasks([Service(ServiceKind.Resolver)] ReadModelDbContext dbContext, IResolverContext context, [Service] NpgsqlHealthChecker npgsqlHealthChecker)
    {
        var workingTasks = dbContext.WorkingTasks
            .AsQueryable()
            .Project(context)
            .Filter(context)
            .Sort(context)
            .ToList(); // Force client-side evaluation

        return workingTasks.AsQueryable();
    }

I don't know why but I always get error after .Sort(context).ToList();. how to fix this?

3 Replies

SWEETPONYOP•9mo ago

full error:

The LINQ expression 'DbSet<WorkingTask>()
    .Where(w => new WorkingTask{ Identity = w.Identity }
    .State == __p_0)' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'.

The LINQ expression 'DbSet<WorkingTask>()
    .Where(w => new WorkingTask{ Identity = w.Identity }
    .State == __p_0)' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'.

but I already use ToList i use HotChocolate

Jimmacle•9mo ago

SQL doesn't know how to create C# objects so new WorkingTask{ Identity = w.Identity } is not something that can be translated into a query it would be fine if you were projecting into it because that's on the C# side after the query runs but you're trying to use that object in a WHERE

SWEETPONYOP•9mo ago

this method used by graphql, let's some examples

{
  workingTasks(
    where: { actualEndTime: {eq: "2024-03-28T14:54:33Z"} }) {
      nodes { 
        identity 
     }
  }
}

{
  workingTasks(
    where: { actualEndTime: {eq: "2024-03-28T14:54:33Z"} }) {
      nodes { 
        identity 
     }
  }
}

{
  workingTasks(
    where: { identity: {eq: "123"} }) {
      nodes { 
        identity 
     }
  }
}

{
  workingTasks(
    where: { identity: {eq: "123"} }) {
      nodes { 
        identity 
     }
  }
}

and if the first one doesn't work at all, the second one works so sometimes it can be translated :OhNo: and I get error after .Filter(context).ToList(), .Project(context).ToList() works good

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System.InvalidOperationException: The LINQ expression 'DbSet<WorkingTask>() .Where(w => new Work