Question

我有两个实体

public class User
{
        [Key]
        public int Id { get; set; } // PK

        // for many-to-many relation with Booking.Members
        public virtual ICollection<Booking> Bookings { get; set; }
}

public class Booking
{
        public Booking()
        {
            Members = new List<User>();
        }

        public int Id { get; set; } // PK

        [ForeignKey("UserByCreated")]
        public int UserByCreatedId { get; set; } // FK
        public virtual User UserByCreated { get; set; } 

        // for many-to-many relation with User.Bookings
        public virtual ICollection<User> Members { get; set; }

}

如上所示，用户和预订有两种不同的关系，一种是多对多关系，另一种是外键关系。

我想要做的是在Bookings表中使用带有NOT NULL条件的UserByCreatedId外键列。

然而，由于与User的另一种关系，似乎不可能。对此有什么解决方案吗？

Answer 1

使用Fluent API配置关系，因为当两个实体之间存在多个关系时，EF无法识别关系。

修改

UserByCreated关系需要更改为可选，以避免多个删除路径问题。

public class Booking { public Booking() { Members = new List<User>(); } public int Id { get; set; } // PK [ForeignKey("UserByCreated")] public int? UserByCreatedId { get; set; } // FK public virtual User UserByCreated { get; set; } public virtual ICollection<User> Members { get; set; } } protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<User>().HasMany(u => u.Bookings) .WithMany(b => b.Members); modelBuilder.Entity<Booking>().HasOptional(u => u.UserByCreated) .WithMany() .HasForeignKey(b => b.UserByCreatedId) .WillCascadeOnDelete(false); }

如何在多个关系中使用NOT NULL设置外键属性

1 个答案: