Question

我收藏了一些模特：

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DTO集合：

class Person
{
    public int Id {get;set;}
    public int Age {get;set;}
    public string Name {get;set;}
}

var collectionModel = new List<Person>{ ... };

所以，class PersonDto { public int Id {get;set;} public int Age {get;set;} public string Name {get;set;} public int RowNumber {get;set;} } var collectionDto = new List<PersonDto>{ ... };我从存储库（数据库）获得，collectionModel我从远程客户端获取。

是否有一种有效的方法来比较这些集合和“应用更改”（更新已更改的实体，删除不存在并添加新实体）collectionDto以将其保存在数据库中？

一个明显的选择 - “手动”比较集合，更新属性，创建和删除对象。但是这段代码变得重复了。

Answer 1

不，没有。如果要避免手动映射属性，可以将Person作为DTO传递，然后将其附加到实体框架上下文。在您的存储库中：

protected virtual void Merge(object modified, object attached)
{
    if (attached != modified)
        DB.Entry(attached).CurrentValues.SetValues(modified);
    else
        DB.Entry(modified).State = EntityState.Modified;
}

然后插入或更新：

public void UpdateSomething(Something obj)
{
    var attached = DB.Somethings.Single(x => x.ID == obj.ID);

    Merge(obj, attached);
    DB.SaveChanges();
}

通过收集DTO来检测模型集合的变化

1 个答案: