I have an ApplicationUser, that has a collection of UserAddress. I simply want to expose endpoints to perform CRUD on these addresses. However when I successfully create an Address (A new row appears in the table, and the User's list of addresses go up by one), when I then go to call another endpoint, the Addresses have reset to 0.

My ApplicationUser model looks like

public class ApplicationUser : IdentityUser
{
    // other stuff..

    public virtual ICollection<UserAddress> UserAddresses { get; set; } = new List<UserAddress>();
}

My UserAddress model

public class UserAddress
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Key]
    public Guid Id { get; set; }

    // Stuff

    public string ApplicationUserId { get; set; }

    public virtual ApplicationUser ApplicationUser { get; set; } = null!;
}

There's no Fluent Api stuff in my DbContext (although I have spent a long time trying some solutions), but I have a public DbSet<UserAddress> UserAddresses { get; set; }

My endpoint for adding an address for a user is simply

    [HttpPost("Create")]
    public async Task<IActionResult> CreateAddress([FromBody] UserAddressDTO request)
    {
        var user = await _userManager.GetUserAsync(User);
        if (user is null)
        {
            return Unauthorized(new ApiError("Could not get a user"));
        }

        var mappedAddress = new UserAddress
        {
            Line1 = request.Line1,
            Line2 = request.Line2,
            City = request.City,
            Country = request.Country,
            Postcode = request.Postcode,
            IsPrimaryAddress = request.IsPrimaryAddress,
            // I don't usually do this, this probably is not necessary but I've been trying a lot of things
            ApplicationUser = user,
            ApplicationUserId = user.Id,
        };

        user.UserAddresses.Add(mappedAddress);
        await _context.SaveChangesAsync();

        // Inspector says user.UserAddresses has a count of 1 at this point. A row is created with the UserId.

        return Ok();
    }

And then when I GET it, it's empty.

    [HttpGet("All")]
    public async Task<IActionResult> GetAll()
    {
        var user = await _userManager.GetUserAsync(User);
        if (user is null)
        {
            return Unauthorized(new ApiError("Could not get a user"));
        }

        // Empty array.
        var addressesForUser = user.UserAddresses;

        return Ok(addressesForUser);
    }

Believe me I have read 999 stack overflow posts, I've read my .NET book, Microsoft docs lol. I am going mad. Usually when I'd do a task like this I'd create the new entity (without any references to what has a collection of it), create a new collection of that entity in the class I want it in, and EF would do some magic and it would just work.

Edit: Added the addresses to the Ok in the GET, I was fiddling with the code, I wouldn't normally return the model objects.

CodePudding user response：

Your forgetting to include the UserAddress, that's why the Address are null

var addressesForUser = user.include(e => e.user.UserAddresses);

I believe your call should be var addressesForUser = applicationuser.include(e => e.applicationuser.UserAddresses);

If you're not using autoInclude. As i can't see you including the List of object. asp.net.core does not autoinclude when calling a List of object inside a class. IT has been recently created in EF6 where they implemented AutoInclude in the ModelBuilder

CodePudding user response：

Thank you to RojhatSefdin for giving me the insight to fix this problem. The code that solved it for me is

    [HttpGet("All")]
    public IActionResult GetAll()
    {
        var userId = _userManager.GetUserId(User);
        var user = _context.Users
            .Include(e => e.UserAddresses)
            .FirstOrDefault(x => x.Id == userId);

        if (user is null)
        {
            return Unauthorized(new ApiError("Could not get a user"));
        }

        return Ok(_mapper.Map<IList<UserAddressDTO>>(user.UserAddresses));
    }

I'm not 100% sure yet but I believe the User I was getting from the UserManager did not include all the other attributes (lazy loading?), so I changed it to just fetch the Id, then I queried the DB with the .Include() to get what I needed.