EF Core 不识别多对多关系

Question

我有多对多关系，但 EF Core 似乎不识别它。

JobOffer

和

JobOfferTag

之间存在关系。

JobOffer

继承自

BaseJobOffer

:

public class BaseJobOffer
{
    [Required]
    [TrimmedStringLength(50, 20)]
    public required string Title { get; set; }

    [Required]
    [TrimmedStringLength(500, 100)]
    public required string Description { get; set; }

    [Required]
    [Range(5, int.MaxValue)]
    public required int PaymentInDollars { get; set; }

    [Required]
    public required PaymentMethod PaymentMethod { get; set; }
    
    public BaseJobOffer()
    {
    }

    [SetsRequiredMembers]
    public BaseJobOffer(BaseJobOffer offer)
    {
        Title = offer.Title;
        Description = offer.Description;
        PaymentInDollars = offer.PaymentInDollars;
        PaymentMethod = offer.PaymentMethod;
    }
}

JobOffer.cs

public class JobOffer : BaseJobOffer
{
    public int Id { get; set; }
    public DateTimeOffset Created { get; private set; } = DateTimeOffset.UtcNow;
    public ICollection<JobOfferTag> Tags = []; // Reference navigation for many to many relationship

    public long UserId { get; set; }
    public ApplicationUser User { get; set; } = null!;

    public JobOffer() : base()
    {
    }

    [SetsRequiredMembers]
    public JobOffer(BaseJobOffer offer) : base(offer)
    {
    }
}

JobOfferTag.cs

public class JobOfferTag
{
    public int Id { get; set; }
    public required string Value { get; set; }

     // Reference navigation for many to many relationship
    public ICollection<JobOffer> JobOffers { get; set; } = []; 
}

EF Core 仅创建

joboffers

和

joboffertag

表，其中

joboffers

具有

JobOfferTagId

列，而根本不应该出现这种情况。我希望 EF Core 创建一个连接表。

Answer 1

我认为为了自动发现多多关系，你需要这样做：

public class JobOffer : BaseJobOffer
{
    public int Id { get; set; }
    public DateTimeOffset Created { get; private set; } = DateTimeOffset.UtcNow;
    public ICollection<JobOfferTag> JobOfferTags { get; set; }

    public long UserId { get; set; }
    public ApplicationUser User { get; set; } = null!;
}

并且：

public class JobOfferTag
{
    public int Id { get; set; }
    public required string Value { get; set; }
    public ICollection<JobOffer> JobOffers { get; set; } 
}

另请参阅所有 EF-Core-约定