c# - EF6 : Configure complex mapping for entities (code first)

Question

我有两个要使用 EF6 Fluent API 配置的数据库实体。

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; }
}

对于任何配置，在尝试将帐户实体实例插入数据库时​​，我总是会收到错误“无法确定相关操作的有效顺序”，如下所示:

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

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

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

Answer 1

幸运的是，EF 推断出外键列 AccountId 和 LastOperationId，所以这对我有用:

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);