postgresql 多对多映射返回错误

Posted 2023-04-12

【中文标题】postgresql 多对多映射返回错误

【英文标题】：postgresql mapping many to many returns error

【发布时间】：2020-05-16 09:10:01

【问题描述】：

您好，我正在为我当前的映射寻找一些有用的提示。当我尝试添加迁移时，它返回以下错误。我不太确定我做错了什么，或者这不是我应该如何映射它们。

System.Reflection.TargetInvocationException：已抛出异常 通过调用的目标。 ---> System.InvalidOperationException： 无法在“Brokers.ManifestToBrokers”和 'ManifestToBroker.ACASBroker'，因为已经存在关系 在“Brokers.ManifestToBrokers”和“ManifestToBroker.ABIBroker”之间。 导航属性只能参与单个关系。

我有 3 个表，Manifest、ManifestToBroker、经纪人。

public class Manifest

    public virtual ManifestToBroker ManifestToBroker  get; set; 
    .......other stuff


public class ManifestToBroker

    public virtual Manifest Manifest  get; set; 

    public int ManifestId  get; set; 

    public int? ABIFilerId  get; set; 

    public int? ACASFilerId  get; set; 

    public int? AMSFilerId  get; set; 

    public virtual Brokers ABIBroker  get; set; 

    public virtual Brokers ACASBroker  get; set; 

    public virtual Brokers AMSBroker  get; set; 


public class Brokers

    [StringLength(32)]
    [Required(AllowEmptyStrings = false)]
    public string Name  get; set; 

    [StringLength(50)]
    public string Description  get; set; 

    [StringLength(100)]
    public string Contacts  get; set; 

    [Required]
    public int BrokerType  get; set; 

    [Required]
    public bool SupportABI  get; set; 

    [Required]
    public bool SupportACAS  get; set; 

    [Required]
    public bool SupportAMS  get; set; 

    public virtual ICollection<ManifestToBroker> ManifestToBrokers  get; set;  = new List<ManifestToBroker>();

为简单起见，我已将所有映射放在 ManifestToBrokerMapper 中。

public class ManifestToBrokerMapping : IntKeyBaseBaseEntityConfiguration<ManifestToBroker>

    protected override void ConfigureThis(EntityTypeBuilder<ManifestToBroker> builder)
    
        builder.HasKey(m => m.Id);
        builder.HasOne(m => m.ABIBroker)
            .WithMany(m => m.ManifestToBrokers)
            .HasForeignKey(m => m.ABIFilerId);
        builder.HasOne(m => m.ACASBroker)
            .WithMany(m => m.ManifestToBrokers)
            .HasForeignKey(m => m.ACASFilerId);
        builder.HasOne(m => m.AMSBroker)
            .WithMany(m => m.ManifestToBrokers)
            .HasForeignKey(m => m.AMSFilerId);
        builder.HasOne(m => m.Manifest)
            .WithOne(m => m.ManifestToBroker)
            .IsRequired();
        builder.HasIndex(m => new  m.ManifestId, m.ABIFilerId ).IsUnique();
        builder.HasIndex(m => new  m.ManifestId, m.ACASFilerId ).IsUnique();
        builder.HasIndex(m => new  m.ManifestId, m.AMSFilerId ).IsUnique();
    

【参考方案1】：

发现问题，brokers表还需要包含每个ManifestToBroker

public virtual ICollection<ManifestToBroker> ABIFilerMTB  get; set;  = new List<ManifestToBroker>();

public virtual ICollection<ManifestToBroker> ACASFilerMTB  get; set;  = new List<ManifestToBroker>();

public virtual ICollection<ManifestToBroker> AMSFilerMTB  get; set;  = new List<ManifestToBroker>();