Entity framework relation mapping is not working - entity-framework

Question

print("Hello World !");
I'm a beginner into the .NET world, i'm trying to use entity framework but i have a problem, my relations entities are not loaded, i followed the microsoft documentation but.
Here are my models :
[Table("Path")]
public class Path
{
[Key]
public int PathId { get; set; }
[Required]
public string Title { get; set; }
public List<Image> Images { get; set; }
[Required]
public string Description { get; set; }
[Required]
public float LocationX { get; set; }
[Required]
public float LocationY { get; set; }
[Required]
public string QrCode { get; set; }
public List<Mark> Marks { get; set; }
}
[Table("Mark")]
public class Mark
{
[Key]
public int MarkId { get; set; }
public int Value { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public Path Path { get; set; }
}
[Table("Image")]
public class Image
{
[Key]
public int ImageId { get; set; }
[Required]
public string Name { get; set; }
public string Description { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public Path Path { get; set; }
[Required]
public string Source { get; set; }
}
For me, everything is ok, i even have the correct entries into my database :
database entries
But my relation dont load when i'm reading database into my controller.
[HttpGet]
public IEnumerable<Path> GetAll()
{
return _context.Paths.ToList();
}
results
I'm sorry, i guess it is probably a stupid beginner error but i dont see what i did wrong. I tried with various database system, with virtual or not ...

Answer 1

Mark your navigation properties as virtual. For example:
[Table("Mark")]
public class Mark
{
[Key]
public int MarkId { get; set; }
public int Value { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public virtual Path Path { get; set; } //Added virtual keyword
}
and a second way to load navigation properties is to use Include while fetching data:
return _context.Marks.Include(x => x.Path).ToList();