EF6：配置实体的复杂映射（代码优先）

Question

我有两个数据库实体需要使用EF6 Fluent API进行配置。

public class Account
{
    public Int32 Id { get; set; }

    public Int32? LastOperationId { get; set; }
    public virtual Operation LastOperation { get; set; }

    public virtual List<Operation> Operations { get; set; }
}

public class Operation
{
    public Int32 Id { get; set; }

    public Int32? AccountId { get; set; }
    public virtual Account Account { get; set; }
}

无论我做怎样的配置，当我尝试像这样将一个账户实体实例插入到数据库时，总是会出现错误“无法确定依赖操作的有效顺序”。

var account = new Account();
var operation = new Operation();

account.Operations = new List<Operation>() { operation };
account.LastOperation = operation;

dbContext.Accounts.Add(account);
dbContext.SaveChanges();

- shadeglare

Answer 1

幸运的是，EF推断出外键列AccountId和LastOperationId，所以这对我很有效：

modelBuilder.Entity<Operation>()
.HasKey(x => x.Id)
.HasOptional(x => x.Account)
.WithMany(x => x.Operations);

modelBuilder.Entity<Account>()
.HasKey(x => x.Id)
.HasOptional(x => x.LastOperation);

- stop-cran

Answer 2

这就是Code-First所需要的完美组合：

public class Account
{
    // One to one to one relationship (shared PK)
     public int Id { get; set; }

     // One to one to one relationship (shared PK)
     public virtual Operation Operation { get; set; }

    // One to many relationship foreign Key
    [InverseProperty("AccountForList")]
     public virtual List<Operation> Operations { get; set; }
   }

   public class Operation
   {
    // One to one to one relationship (shared PK)
    [ForeignKey("Account")]
     public Int32 Id { get; set; }

     // One to one to one relationship (shared PK)
     public virtual Account Account { get; set; }

     // One to many relationship foreign Key
     public Int32? AccountForListId { get; set; }

     // One to many relationship foreign Key
     [ForeignKey("AccountForListId")]
     public virtual Account AccountForList { get; set; }
     }

账户表：列名：Id

操作表：列名：Id（与账户表共享），AccountForListId（1..n）

- Bassam Alugili