Is it possible to map nested properties?

[danielniccoli]

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Is it possible to map nested properties?

I have a Cosmos DB item that looks like this:

{
    "id": "955175a3-4d9b-495d-884f-a0b7a632ee88",
    "blueprint": {
        "description": "Decodes a pulse signal at base.\n\nGenerate a pulse signal at outpost by adding a leading and trailing edge detector to an SR latch, and outputting 3 signals at the same time: like [Stone][1][Green]\n\nThen decode it at base using this circuit. Turns light on at green, turns it off on red.",
        "icons": […],
        "entities": […],
        "item": "blueprint",
        "label": "Decode at base",
        "version": 281479276658688
    },
    "_rid": "EVAHAJ1MVP8DAAAAAAAAAA==",
    "_self": "dbs/EVAHAA==/colls/EVAHAJ1MVP8=/docs/EVAHAJ1MVP8DAAAAAAAAAA==/",
    "_etag": "\"5a00217a-0000-0d00-0000-64395f0e0000\"",
    "_attachments": "attachments/",
    "_ts": 1681481486
}

My model at the moment is this:

blueprint.cs

namespace FactorioStudio.Data;

public class Blueprint
{
    public Guid Id { get; set; }
    public string Label? { get; set; }
    public string Description? { get; set; }
}

FactorioStudioContext.cs

using Microsoft.EntityFrameworkCore;

namespace FactorioStudio.Data;

public class FactorioStudioContext : DbContext
{

    public FactorioStudioContext(DbContextOptions<FactorioStudioContext> options) : base(options)    {    }
    public DbSet<Blueprint> Blueprints { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Blueprint>().Property(e => e.Id).ToJsonProperty("id");
        modelBuilder.Entity<Blueprint>()
            .ToContainer(nameof(Blueprints))
            .HasPartitionKey(o => o.Id)
            .HasNoDiscriminator()
            .UseETagConcurrency();

        base.OnModelCreating(modelBuilder);
    }
}

Theoretically, it should be possible, no? I can query the database with this query and it returns the result as expected.

SELECT c.blueprint.label, c.blueprint.description FROM c 

[
    {},
    {},
    {
        "label": "Decode at base",
        "description": "Decodes a pulse signal at base.\n\nGenerate a pulse signal at outpost by adding a leading and trailing edge detector to an SR latch, and outputting 3 signals at the same time: like [Stone][1][Green]\n\nThen decode it at base using this circuit. Turns light on at green, turns it off on red."
    }
]

So I'm hoping there is something along the lines of

modelBuilder.Entity<Blueprint>().Property(e => e.Label).ToJsonProperty("/blueprint/label");

that maps property Label to "/blueprint/label"?

Include provider and version information

EF Core version: 7
Database provider: CosmosDB
Target framework: .NET 7.0
Operating system: Windows 11
IDE: Visual Studio 2022

[ajcvickers]

@danielniccoli We discussed this, and it is not something we are going to implement. We currently expect the shape of the document to match the shape of the mapped entity types. That being said, weakly typed JSON mapping could be used for this, which is being tracked by #28871.