我有兩個對象：用戶和關系。為我系統的每個用戶創建一個用戶對象，并且將為每個用戶創建多個關系，具體取決于他們添加為朋友的人數。對象如下所示public class User : IdentityUser {}public class Relationship { // User who created the relationship public User User {get;set;} // User who the creation user is friends with public User Friend {get;set;} // Enum of Status (Approved, Pending, Denied, Blocked) public RelationshipStatus RelationshipStatus {get;set;} public DateTime RelationshipCreationDate {get;set;}}每個用戶可以有多個匹配的記錄，Relationship.User也可以有多個匹配的記錄Relationship.Friend。我的 DbContext 設置如下OnModelCreating：protected override void OnModelCreating(ModelBuilder builder){ builder.Entity<Relationship>(relationship => { relationship.HasOne(r => r.User).WithMany(u => u.Friends); }); }我是 Entity 的新手，所以這可能是微不足道的 - 我缺少什么來設置我所描述的關系？謝謝！編輯：更具體地說，這是我得到的錯誤：InvalidOperationException: Unable to determine the relationship represented by navigation property 'Relationship.Friend' of type 'User'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'編輯 2：在重新考慮我的流程后，我采取了不同的方法，并使用關系來包括追隨者和追隨者，而不是集體朋友列表（無論如何更適合我的商業模式）。我通過以下方式實現了這一點：public class User : IdentityUser { [InverseProperty("Friend")] public List<Relationship> Followers {get;set;} [InverseProperty("User")] public List<Relationship> Following {get;set;}}我很好奇是否有人在我的解決方案之外有解決原始問題的方法，但是，這目前有效，似乎最適合我。
2 回答
拉莫斯之舞
TA貢獻1820條經驗 獲得超10個贊
您是否嘗試向用戶類添加關系列表，即
public class User : IdentityUser {
List<Relationship> Relationships {get;set;}
}
這可能有助于 EF 充分理解這種關系。
慕容森
TA貢獻1853條經驗 獲得超18個贊
看起來您正在嘗試many-to-many使用相同的實體進行配置。為此，請編寫您的User和Relationship模型類，如下所示：
public class User : IdentityUser
{
public List<Relationship> UserFriends { get; set; }
public List<Relationship> FriendUsers { get; set; }
}
public class Relationship {
public string UserId {get; set;} // `UserId` type is string as you are using default identity
public User User {get;set;}
public string FriendId {get; set;}
public User Friend {get;set;}
// Enum of Status (Approved, Pending, Denied, Blocked)
public RelationshipStatus RelationshipStatus {get;set;}
public DateTime RelationshipCreationDate {get;set;}
}
然后在模型構建器實體配置中：
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Relationship>().HasKey(r => new {r.UserId, r.FriendId});
modelBuilder.Entity<Relationship>()
.HasOne(r => r.User)
.WithMany(u => u.UserFriends)
.HasForeignKey(r => r.UserId).OnDelete(DeleteBehavior.Restrict);
modelBuilder.Entity<Relationship>()
.HasOne(r => r.Friend)
.WithMany(f => f.FriendUsers)
.HasForeignKey(r => r.FriendId).OnDelete(DeleteBehavior.Restrict);
}
現在它應該可以正常工作了！
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