EF Core related data is null with AutoMapper

Question

In my app one case can have many companies.

My models:

public class Case
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid Id { get; set; }
    public string Name { get; set; }
    public IList<CaseCompany> CaseCompanies { get; set; }
}

public class CaseInput
{
    public Guid Id { get; set; }
    [Required]
    public string Name { get; set; }
    public IList<CaseCompanyInput> CaseCompanyInputs { get; set; }
}

public class Company
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid Id { get; set; }
    public string Name { get; set; }
}

public class CompanyInput
{
    public Guid Id { get; set; }
    [Required]
    public string Name { get; set; }
}

public class CaseCompany
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid Id { get; set; }
    public Guid CaseId { get; set; }
    public Guid CompanyId { get; set; }
    public class Case Case { get; set; }
    public class Company Company { get; set; }
}

public class CaseCompanyInput
{
    public Guid Id { get; set; }
    public Guid CaseId { get; set; }
    public Guid CompanyId { get; set; }
    public class CaseInput CaseInput { get; set; }
    public class CompanyInput CompanyInput { get; set; }
}

AutoMapperProfiles.cs:

// In Startup.cs: services.AddAutoMapper(typeof(AutoMapperProfiles));

public class AutoMapperProfiles : Profile
{
    public AutoMapperProfiles()
    {
        CreateMap<Case, CaseInput>().ReverseMap();
        CreateMap<CaseCompany, CaseCompanyInput>().ReverseMap();
        CreateMap<Company, CompanyInput>().ReverseMap();
    }
}

EditCase.cs:

private readonly DBContext _dbContext;
private readonly IMapper _mapper;

[BindProperty]
public CaseInput CaseInput { get; set; }

public EditCase(DBContext dbContext, IMapper mapper)
{
    _dbContext = dbContext;
    _mapper = mapper;
}

public async Task<IActionResult> OnGetAsync(Guid caseId)
{
    var getCase = await _dbContext.Cases.Include(x => x.CaseCompanies).ThenInclude(x => x.Company).FirstOrDefaultAsync(x => x.Id == caseId);
    CaseInput = _mapper.Map<CaseInput>(getCase);

    Console.WriteLine(getCase.CaseCompanies[0].Company.Name) // gets the company name
    Console.WriteLine(CaseInput.CaseCompanyInputs[0].CompanyInput.Name) // CaseInput.Name is not null but CaseCompanyInputs is null

    return Page();

}

I've also tried:

CaseInput = await _dbContext.Cases.ProjectTo<CaseInput>(_mapper.ConfigurationProvider).FirstOrDefaultAsync(x => x.Id == caseId);

and

CaseInput = await _dbContext.Cases.Include(x => x.CaseCompanies).ThenInclude(x => x.Company).ProjectTo<CaseInput>(_mapper.ConfigurationProvider).FirstOrDefaultAsync(x => x.Id == caseId);

with the same result: CaseCompanyInputs is null.

My best guess is that it's an error in the relations of the input models, but I just can't see it. I believe I've followed the naming conventions to make the relations right.

Any help would be appreciated.

is it `getCase.CaseCompany.Company` or `getCase.CaseCompany[0].Company`? in your code — Vivek Nuna, Mar 03 '21 at 11:11
Why don't you check the generated SQL? That should tell you what's wrong. — Lucian Bargaoanu, Mar 03 '21 at 11:51

ash · Accepted Answer · 2021-03-03T14:08:19.557

For automapping to work, you have to rename ur destination property name the same as the source property name

public class CaseInput
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    //public IList<CaseCompanyInput> CaseCompanyInputs { get; set; }
    public IList<CaseCompanyInput> CaseCompanies { get; set; }
}

public class CaseCompanyInput
{
    public Guid Id { get; set; }
    public Guid CaseId { get; set; }
    public Guid CompanyId { get; set; }
    //public CaseInput CaseInput { get; set; }
    public CaseInput Case { get; set; }
    //public CompanyInput CompanyInput { get; set; }
    public CompanyInput Company { get; set; }
}

If you don't want to change the property names, change ur configuration to the following.

CreateMap<Case, CaseInput>()
    .ForMember(dest => dest.CaseCompanyInputs, opt => opt.MapFrom(src => src.CaseCompanies));

CreateMap<CaseCompany, CaseCompanyInput>()
    .ForMember(dest => dest.CaseInput, opt => opt.MapFrom(src => src.Case))
    .ForMember(dest => dest.CompanyInput, opt => opt.MapFrom(src => src.Company));

Thank you, @ash! Changed the names in the models and it worked. — Mads, Mar 04 '21 at 08:02

EF Core related data is null with AutoMapper

1 Answers1