The property 'x' is not a navigation property of entity type 'y'

Question

I'm using EF Core with ASP Core 2.0. Using latest Identity framework. I get this exception on page All.

InvalidOperationException: The property 'User' is not a navigation property of entity type 'Gallery'. The 'Include(string)' method can only be used with a '.' separated list of navigation property names.

ApplicationUser looks like:

public class ApplicationUser : IdentityUser<Guid>
{
    public ICollection<Gallery> Galleries { get; set; }
}

Entity Gallery looks like:

public class Gallery
{
    public int Id { get; set; }
    public Guid UserId { get; set; }
    public string Title { get; set; }
    public int? ArticleId { get; set; }
    public string Photos { get; set; }
    public DateTime CreatedAt { get; set; }
    public DateTime UpdatedAt { get; set; }

    public Article Article { get; set; }
    public ApplicationUser User { get; set; }

    [NotMapped]
    public List<string> PhotosList
    {
        get { return Photos?.Split('|').ToList(); }
        set { Photos = string.Join("|", value); }
    }
}

Controller for View looks like:

public async Task<IActionResult> All()
    {
        var databaseContext = db.Galleries.Include(x => x.Article).Include(x => x.User);

        return View(await databaseContext.ToListAsync());
    }

I have no idea why it dont crash on Article..

Database is up-to-date.

Does [this](https://stackoverflow.com/questions/36047948/ef-the-navigation-property-is-not-a-declared-property-on-type) help? — kabanus, Oct 19 '17 at 20:29
Cristic: well I dont have option x.ApplicationUser cause I defined navigation named User not ApplicationUser.. ApplicationUser is class not variable name — user1085907, Oct 19 '17 at 20:38
Worth noting. I made a mistake in my scenario. I was using Database.Order.Include(o => o.ShopId) when in fact it should have been Database.Order.Include(o => o.Shop) - literally a typo in my case - just check you are not accidentally linking to an Id as you would in a SQL query. — Andy, Jul 21 '21 at 07:38

Sam I am says Reinstate Monica · Accepted Answer · 2017-10-20T14:14:34.677

2

add a ForeignKey attribute

using System.ComponentModel.DataAnnotations.Schema;

...

[ForeignKey("Article")]
public int? ArticleId { get; set; }

[ForeignKey("User")]
public Guid UserId { get; set; }

You can also put the attribute on the navigation property

[ForeignKey("UserId")]
public ApplicationUser User { get; set; }

Also, make sure your dbContext inherits from IdentityDbContext<ApplicationUser, ...>

edited Oct 20 '17 at 14:14

answered Oct 19 '17 at 20:41

Sam I am says Reinstate Monica

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Well it still doesnt resolve my problem.. even with attribute :( Any next idea? Thanks – user1085907 Oct 19 '17 at 20:47
@user1085907 try the version with the attribute on the `User` – Sam I am says Reinstate Monica Oct 19 '17 at 20:49
@user1085907 what does your dbContext declaration look like? does it inherit from `IdentityDbContext`? – Sam I am says Reinstate Monica Oct 19 '17 at 21:59
Actually no, it inherits DbContext, I using two DatabaseContexts, 1 only for Identity and second for my entities with included ApplicationUser (OnModelCreating I ignore ApplicationUser table). Should I use only 1 context? – user1085907 Oct 19 '17 at 22:11
1

@user1085907 I think that using 1 context would solve your navigation property issue. – Sam I am says Reinstate Monica Oct 19 '17 at 22:13
Okay it works with context that inherits from IdentityDbContext, thanks for resolving, edit it into post pls if anyone has same trouble :) – user1085907 Oct 20 '17 at 11:21

score 2 · Answer 2 · edited Nov 20 '22 at 13:50

2

You can run into this if you manually add extra properties to Models.

To troubleshoot it, run SQL Profiler and capture the RAW SQL, execute the SQL against the database and see why the query doesn't work, ie which property 'x' is not a navigation property of entity type 'y'.

Then go to the model and remove the extra property you added manually.

PS: If you don't have a SQL dB you can use another profiler. Alternatively just check the diffs in source control.

edited Nov 20 '22 at 13:50

halfer

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answered Apr 04 '19 at 02:19

Jeremy Thompson

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This is definitely the root cause, but manually added properties are also necessary to programs. A better solution will be to detect if the property is part of the underlying model (IE a boolean result telling us if the property is valid for LINQ-to-SQL). The error already tells us which property it doesn't like. – Tim May 11 '21 at 18:47

The property 'x' is not a navigation property of entity type 'y'

2 Answers2

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