[英]EF6: Configure complex mapping for entities (code first)
I've got two db entities I want to configure using EF6 fluent API. 我有两个db实体,我想使用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; }
}
For any configuration I always get an error "Unable to determine a valid ordering for dependent operations" when trying to insert an account entity instance into a db like this: 对于任何配置,当尝试将帐户实体实例插入到数据库中时,我总是会收到错误“无法确定相关操作的有效排序”,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();
Fortunately, EF infers foreign key columns AccountId
and LastOperationId
, so this works for me: 幸运的是,EF推断外键列
AccountId
和LastOperationId
,所以这对我LastOperationId
:
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);
this is the combination excatly what you need in Code-First: 这是您在Code-First中所需要的组合:
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; }
}
Account Table: columnname : Id 帐户表:columnname:Id
Operation Table: column name Id(shared with Account), AccountForListId (1..n) 操作表:列名Id(与Account共享),AccountForListId(1..n)
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