与 FOREIGN KEY 冲突

Posted 2023-04-12

【中文标题】与 FOREIGN KEY 冲突

【英文标题】：Conflicted with the FOREIGN KEY

【发布时间】：2011-10-17 15:04:28

【问题描述】：

保存对象对时出错。

代码

数据类

public class User

    public Guid Id  get; set; 
    public string FirstName  get; set; 
    public string LastName  get; set; 
    public string Email  get; set; 
    public string Password  get; set; 
    public bool IsApproved  get; set; 
    public bool IsBlock  get; set; 
    public bool IsGuest  get; set; 
    public string CodeGuest  get; set; 
    public Gender Gender  get; set; 
    public DateTime? Birth  get; set; 
    public virtual ICollection<Role> Roles  get; set; 
    public virtual Couple Couple  get; set; 

    public User()
    
        Id = Guid.NewGuid();
    



public class Couple

    public Guid Id  get; private set; 
    public string UrlKeyword  get; set; 
    public virtual User Groom  get; set; 
    public virtual User Bride  get; set; 
    public DateTime? Marriage  get; set; 
    public DateTime? Dating  get; set; 
    public DateTime? Engagement  get; set; 

    public virtual ICollection<User> Users  get; set; 

    public Couple()
    
        Id = Guid.NewGuid();
    

上下文和配置

public class DataContext : DbContext

    #region Collections

    public DbSet<Role> Roles  get; set; 
    public DbSet<User> Users  get; set; 
    public DbSet<Couple> Couples  get; set; 

    #endregion

    public DataContext()
    
        Database.SetInitializer(new AndMarriedInitializer());

        if (!Database.CreateIfNotExists())
            Database.CreateIfNotExists();
    

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    
        modelBuilder.Configurations.Add(new UserConfiguration());
        base.OnModelCreating(modelBuilder);
    


public class UserConfiguration : EntityTypeConfiguration<User>

    public UserConfiguration()
    
        HasKey(p => p.Id).
            Property(p => p.Id)
                .IsRequired();

        Property(p => p.FirstName)
            .HasMaxLength(60)
            .IsRequired();

        Property(p => p.LastName)
            .HasMaxLength(120)
            .IsRequired();

        Property(p => p.Email)
            .HasMaxLength(120)
            .IsRequired();

        Property(p => p.Password)
            .HasMaxLength(60);

        Property(p => p.CodeGuest)
            .HasMaxLength(60);

        HasRequired(u => u.Couple).WithRequiredPrincipal();
    


public class CoupleConfiguration : EntityTypeConfiguration<Couple>

    public CoupleConfiguration()
    
        HasKey(p => p.Id)
            .Property(p => p.Id)
            .IsRequired();

        Property(p => p.UrlKeyword)
            .IsRequired()
            .HasMaxLength(25);

        HasRequired(p => p.Groom).WithRequiredPrincipal().WillCascadeOnDelete();
        HasRequired(p => p.Bride).WithRequiredPrincipal().WillCascadeOnDelete();
    


public class AndMarriedInitializer : DropCreateDatabaseIfModelChanges<DataContext>

    protected override void Seed(DataContext context)
    
        context.Roles.Add(new Role
                              
                                  Name = Constants.RoleAdmin
                              );
        context.Roles.Add(new Role
                              
                                  Name = Constants.RoleCouple
                              );
        context.Roles.Add(new Role
                              
                                  Name = Constants.RoleGuest
                              );

        context.SaveChanges();

        base.Seed(context);
    

问题

不知道配置是否正确，但是我们与用户的情侣关系是：1对1。

不太明白WithRequiredPrincipal和WithRequiredDependent是怎么回事

错误

关于 SaveChanges() =>

The INSERT statement conflicted with the FOREIGN KEY constraint "User_Couple". The conflict occurred in database "andmarried", table "dbo.Users", column 'Id'. The statement has been terminated.

【参考方案1】：

有了这行代码：

public UserConfiguration()

//...
    HasRequired(u => u.Couple).WithRequiredPrincipal();
//...

您要求所有用户始终“耦合”。

那么，当您提交更改时，您创建的所有用户都结婚了吗？如果不是，请删除该外键约束。 （把这对夫妇留在里面，你应该没事）

【讨论】：

是的，但我想要的是每个用户都与一对相关联。定义是情侣还是客人的是角色；

在任何情况下，听起来您都在提交一个数据库状态，其中用户存在而没有夫妻。也许自动提交是一个问题？你能展示实际调用这些对象的代码吗？即：正在创建和保存什么，然后实际行因异常而失败？注意：根据您的上一条评论，用户 Couple 听起来像是 2 1 或许多 1。

public Couple Add(Couple entity) // Add Roles var role = (from r in RoleRepository.GetAll() where r.Name == Constants.RoleCouple select r).SingleOrDefault(); entity.Bride.Roles.Add(role); entity.Groom.Roles.Add(role); //entity.Users.Add(entity.Bride); //Problem here //entity.Users.Add(entity.Groom); //Problem here return Repository.Add(entity); 查看//Problem here 行 不知道我是否将此行注释掉，或者删除注释。关系是 1 个用户的 2 对情侣

如果我删除评论会出现以下错误：Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values.

你有没有为用户情侣关系尝试过WithMany()？