Question

我正在尝试使用linq2sql将它们插入两个关联的表中，但是我的代码仅插入一个实体（电子邮件），但没有任何异常-仅未插入另一个实体（附件）。

我认为我在关联中的某个地方有一个错误，但是我不知道如何正确设置它。

感谢帮助。

插入代码：

using (TransactionScope main_transaction = new TransactionScope(TransactionScopeOption.Required, TimeSpan.FromSeconds(120)))
            {

                foreach (var attachment in attachmets)
                    email.Attachments.Add(attachment);

                _emails.InsertOnSubmit(email);

                _context.SubmitChanges();

                main_transaction.Complete();
            }

Pocos：

[Table(Name = "maily")]
internal class Email
{
    private EntitySet<Attachment> _attachments;

    public Email()
    {
        this._attachments = new EntitySet<Attachment>(); 
    }

    [Column(IsPrimaryKey = true, IsDbGenerated = true, Name = "ID_mailu", AutoSync = AutoSync.OnInsert)]
    public virtual int ID_mailu { get; set; }



    [Association(Storage = "_attachments", OtherKey = "id_mailu")]
    public ICollection<Attachment> Attachments
    {
        get { return _attachments.ToList(); }
        set { _attachments.Assign(value); }
    }
}

[Table(Name = "MailPrilohy")]
internal class Attachment
{
    private EntityRef<Email> _email;

    public Attachment()
    {
        _email = default(EntityRef<Email>);
    }

    [Column(IsPrimaryKey =true, IsDbGenerated = true, Name = "id_prilohy", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
    public int Id_Prilohy { get; set; }

    [Column(Name = "id_mailu", CanBeNull = false, IsDbGenerated = true)]
    public int id_mailu { get; set; }

    [Association(Storage = "_email", ThisKey = "id_mailu", OtherKey = "ID_mailu", IsForeignKey = true)]
    public Email Email
    {
        get { return _email.Entity; }
        set { _email.Entity = value; }
    }

}

}

Answer 1

为了通过LINQ插入到两个相关的表中，如果您的表之间具有主键/外键关系，那么您还有两个可以相互链接的对象。一个非常基本的例子：

MyDataContext _dbcontext = new MyDataContext();   
ItemType t = new ItemType();
t.type= "Snacks";
MenuItem m = new MenuItem();
m.type= "Party Snacks";
t.ItemType.Add(m);

_dbcontext.ItemTypes.Add(t);
_dbcontext.SubmitChanges();

上面的示例在将更改提交到ItemTypes实体时将添加您的对象和所有链接的对象。另外请注意，要使此功能正常工作，两个表中都必须有一个主键。否则LINQ无法为您提供链接的可能性。

Answer 2

所以我刚刚解决了这个问题...

问题出在几个地方。

1s是关联错过的外键属性..

[Association(Storage = "_email", ThisKey = "id_mailu", OtherKey = "ID_mailu", IsForeignKey = true)]
        public Email Email
        {
            get { return _email.Entity; }
            set { _email.Entity = value;}
        }

接下来，我应该插入附件->而不是电子邮件。

_context.Attachments.InsertAllOnSubmit(attachmets);

Answer 3

您能尝试看看是否适合您吗？

using (TransactionScope main_transaction = new TransactionScope(TransactionScopeOption.Required, TimeSpan.FromSeconds(120)))
            {

                foreach (var attachment in attachmets)
                    attachment.Email = email; // only this line changed

                _emails.InsertOnSubmit(email);

                _context.SubmitChanges();

                main_transaction.Complete();
            }

Linq2SQL不插入相关实体

3 个答案: