Question

我正在访问Microsoft的多对多ef核心示例

https://docs.microsoft.com/en-us/ef/core/modeling/relationships#many-to-many

但是会出现自引用循环错误。

这是我的实体：

public class Card
{
    public Guid Id { get; set; }

    public string CardNumber { get; set; }
    public CardType CardType { get; set; }

    public string Name { get; set; }
    public string Description { get; set; }
    public int PassCode { get; set; }

    public List<CardSet> CardSets { get; set; }

    public Card()
    {
        CardSets = new List<CardSet>();
    }
}

public class Set
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    public List<CardSet> CardSets { get; set; }

    public Set()
    {
        CardSets = new List<CardSet>();
    }
}
// join entity
public class CardSet
{
    public Guid SetId { get; set; }
    public Set Set { get; set; }

    public Guid CardId { get; set; }
    public Card Card { get; set; }
}

这是我的OnModelCreating：

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<CardSet>().HasKey(cs => new {cs.CardId, cs.SetId});

        modelBuilder.Entity<CardSet>()
            .HasOne(cs => cs.Card)
            .WithMany(c => c.CardSets)
            .HasForeignKey(cs => cs.CardId);

        modelBuilder.Entity<CardSet>()
            .HasOne(cs => cs.Set)
            .WithMany(s => s.CardSets)
            .HasForeignKey(cs => cs.SetId);
    }

以下是通过电话卡获得套装的电话：

    public Set GetSetWithCards(Guid setId)
    {
        return context
               .Sets
               .Include(s => s.CardSets)
               .ThenInclude(cs => cs.Card)
               .FirstOrDefault(s => s.Id == setId);
    }

错误：

 Newtonsoft.Json.JsonSerializationException: Self referencing loop
 detected for property 'set' with type
 'Tools.Entities.Set'. Path 'cardSets[0]'.

Answer 1

您所有的实体配置都是正确的，并且根据错误消息，当您尝试将结果数据序列化为JSON时，似乎出现了问题。

查看此答案以获取详细信息：JSON.NET Error Self referencing loop detected for type

实体框架核心2.2多对多自引用循环

1 个答案: