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实体框架6克隆数据库中的父级和所有子级

clone entity-framework-6 entity-framework asp.net-mvc c#

GustavoZafra · 技术社区 · 8 年前

我正在尝试复制一个对象(Parent)及其关系(Children1、Children 2、Childeren 3和Childrren4),为数据库中的每个对象创建一个新id,但仍然失败。有什么方法可以做到这一点吗?

下面是对象的结构及其关系。拜托,我需要很多人来帮助我。

public class Parent
{
    [PrimaryKey]
    public long IdParent {get; set;}
    public string Description {get; set;}
    public string OtherValue {get; set;}

    public virtual ICollection<Children1> Childrens1 {get; set;}
}

public class Children1
{
    [PrimaryKey]
    public long IdParent {get; set;}
    [PrimaryKey]
    public long IdChildren1 {get; set;}
    public string Description {get; set;}

    public virtual Parent Parent {get; set;}
    public virtual ICollection<Children1> Childrens1 {get; set;}
}

public class Children2
{
    [PrimaryKey]
    public long IdParent {get; set;}
    [PrimaryKey]
    public long IdChildren1 {get; set;}
    [PrimaryKey]
    public long IdChildren2 {get; set;}
    public string Description {get; set;}

    public virtual Children1 Children1 {get; set;}
}

public class Children3
{
    [PrimaryKey]
    public long IdParent {get; set;}
    [PrimaryKey]
    public long IdChildren1 {get; set;}
    [PrimaryKey]
    public long IdChildren3 {get; set;}
    public string Description {get; set;}

    public virtual Children1 Children1 {get; set;}
    public virtual ICollection<Children4> Childrens4 {get; set;}
}

public class Children3
{
    [PrimaryKey]
    public long IdParent {get; set;}
    [PrimaryKey]
    public long IdChildren1 {get; set;}
    [PrimaryKey]
    public long IdChildren3 {get; set;}
    [PrimaryKey]
    public long IdChildren4 {get; set;}
    public string Description {get; set;}

    public virtual Children3 Children3 {get; set;}
}

2 回复 | 直到 8 年前

Cinchoo 8 年前

这就是我处理这件事的方式。从上下文中检索所有父级子级,不进行跟踪,并将它们添加回上下文以进行克隆。

(我只是展示了基于实体图的示例代码,因为实体模型类与之不匹配。)

public Item DeepClone(Parent item)
{
    Parent itemClone = db.Parents
        .Include(i => i.Childrens1.Select(c => c.Childrens2 ))
        .Include(i => i.Childrens3.Select(c => c.Childrens4 ))
        .AsNoTracking()
        .FirstOrDefault(i => i.IdParent == item.IdParent);

    db.Items.Add(itemClone);
    db.SaveChanges();
    return itemClone;
}

Riaz Raza 8 年前

在这种情况下,最好的做法是从上下文中分离对象,然后重新插入,但这种方法的唯一问题是分离父对象不会分离相关对象,您必须显式分离所有相关对象,然后再重新插入它们以生成它们的克隆

context.Detach(object);
context.SaveChanges(object);
context.Entry(object).State = EntityState.Added;
context.SaveChanges();