LINQ question in .NET 6 EF CORE conversion

Question

I currently have a .NET 4 WebAPI using Entity Framework 3 that I'm upgrading to .NET 6 EF CORE. I currently have a LINQ Query that looks like this (and works fine)

[HttpGet]  
public async Task<ActionResults> GetCars()  
{  
   var x = from f in _context.CarMakes  
   group c in f.Make into m  
   select new { c.Key };  
  
return Json(new   
{   
        data = await x  
        .ToListAsync()  
     };  
        
  
}  

this returns me:
Chevy
Ford
Volvo
Toyota

and so on.

I'm trying to use this same query in a .NET 6 WebAPI that is using EF CORE, it fails, and kicks back an error:

in the .NET 6 EF CORE project, I have:

[HttpGet]  
public async Task<ActionResults<IEnumerable<CarMakes>>>> GetCars()  
{  
   var x = from f in _context.CarMakes  
   group c in f.Make into m  
   select new { c.Key };  
  
return await x.ToListAsync();  
        
  
}  

I get an error message of: [ cannot implicity convert type 'System.Threading.Task.Task<System.Collections.GenericLis>> ] to Microsoft.AspNetCore.Mvc.ActionResults<System.Collections.Generic.IEnumerable<app.CarMakes>

Answer 1

You forgot the await.

return await x.ToListAsync();  

Answer 2

I changed the code to this and it works:

   [HttpGet]  
    public async Task<ActionResults<IEnumerable<CarMakes>>>> GetCars()  
    {  
       var x = from f in _context.CarMakes  
       group c in f.League into m  
       order by c.key  
       select new { c.Key };  
  
 return Ok(await q.ToListAsync());  
            
  
    }  

even with this, how can I grab the column name instead of the .Key?

Answer 3

you don't show you class definition, but assuming make is a string, then

   var x = from f in _context.CarMakes  
    group c in f.Make into m  
    select new { c.Key };  

when the converted to json looks like:

[{key: "Ford"}, {key: "Chevy", ...]

not a list of string or a list of CarMakes, but a list of an anonymous objects. in net 6 this would be a list of objects not CarMakes:

[HttpGet]  
 public async Task<ActionResults<IEnumerable<object>>> GetCars()  
 {  
    var x = from f in _context.CarMakes  
    group c in f.Make into m  
    select new { c.Key };  
      
    return await x.ToListAsync();  
 }