无法从模型中获取ASP.Net中的相关数据

Question

我刚刚开始学习ASP.Net Core，并且在关系方面存在一些问题。

在我的Beer模型中，我具有以下导航属性：

/* Navigation Properties */
public int BreweryID { get; set; }
public Brewery Brewery { get; set; }

在我的Brewery模型中，我具有以下导航属性：

/* Navigation Properties */
public ICollection<Beer> Beers { get; set; }

我的dbContext看起来像这样：

modelBuiler.Entity<Beer>()
            .HasOne(c => c.Brewery)
            .WithMany(u => u.Beers)
            .HasForeignKey(c => c.BreweryID)
            .IsRequired()
            .OnDelete(DeleteBehavior.Restrict);

在控制器中，我这样询问数据：

// GET: api/brewery
    [HttpGet]
    public async Task<ActionResult<IEnumerable<Brewery>>> GetBreweries()
    {
        return await _context.Breweries.ToListAsync();
    }

现在，我的数据库中有一些测试数据。当我向邮递员发出“获取请求”时，啤酒厂没有显示任何相关的啤酒。

在邮递员中，它看起来像这样：

//啤酒

{
    "id": 11,
    "name": "test",
    "brand": "test",
    "alcoholContent": 2,
    "platoScale": 4,
    "description": "test",
    "breweryID": 7,
    "brewery": null,
    "imageID": 3,
    "image": null,
    "foodpairings": null,
    "categoryID": 1,
    "category": null,
    "favorites": null
},
{
    "id": 12,
    "name": "test",
    "brand": "test",
    "alcoholContent": 4,
    "platoScale": 7,
    "description": "test",
    "breweryID": 7,
    "brewery": null,
    "imageID": 4,
    "image": null,
    "foodpairings": null,
    "categoryID": 1,
    "category": null,
    "favorites": null
},

//啤酒厂

 {
    "id": 7,
    "name": "Moortgat",
    "address": "test",
    "founder": "test",
    "foundationYear": "2008-01-10T00:00:00.123",
    "description": "test",
    "website": "test",
    "beers": null,
    "imageID": 3,
    "image": null
}

有什么建议吗？

Answer 1

查询中不包含Beer的相关实体。请包括相同的_context.Breweries.Include（brewery => brewery.Beers）

Answer 2

尝试一下。

return await _context.Breweries
    .Include(x => x.Beers)
    .ToListAsync();

https://docs.microsoft.com/en-us/ef/core/querying/related-data

Answer 3

您现在遇到的确切问题已在此线程中指定

.Net Core 3 and EF Core 3 Include Problem (JsonException) [Solved]