Enitiy框架更新相关实体

问题描述

您好我在更新相关实体时遇到问题。所以我的Document实体有一组Customers。当我添加一个新文档时，我可以添加尽可能多的客户，但是当我更新时，只更新标量属性。



这是我更新文档的代码...

Hello I have a problem when updating related entities. So my Document entity has a collection of Customers. When Im adding a new document I can add as many customers as I want, but when Im updating only scalar properties are updated.

This is my code for updating a document...

public static bool UpdateDocument(Document documentToUpdate)
{
    using (MyDbContext = new MyDbContext())
    {
        // attaching the entity does not help
        if (context.Entry(documentToUpdate).State == EntityState.Detached)
            context.Documents.Attach(documentToUpdate);

        context.Entry(documentToUpdate).State = EntityState.Modified;
        context.SaveChanges();
        return true;
    }
}

关于文档操作，添加和删除客户的废话是在另一个层/项目中完成的，所以我的问题是我如何继续这个？或者如何在此方法中更新相关的客户集合？或者shuld我使用不同的方法只是为了客户操作。



类似

Evrything regarding document manipulation, adding and removing customers is done in another layer/project, so my question is how shuld I proceed with this? Or how do I update the related customer collection here in this method? Or shuld I use a different method just for customer manipulation.

Something like

public static void UpdateCustomersOnDoc(Document doc)
{
    using (MyDbContext context = new MyDbContext())
    {
        Document tempDoc = DocumentCRUD.GetByID(doc.Id);
        // remove the customers from the document (database)
        tempDoc.Customers.Clear();

        // add customers from the modified document
        foreach(var cust in doc.Customers)
        {
            docTemp.Customers.Add(cust);
        }
        // save changes to the context
        context.SaveChanges();
    }
}

推荐答案

public static bool UpdateDocument(Document documentToUpdate)
{
    using (MyDbContext = new MyDbContext())
    {
        Document doc = MyDbContext.FirstOrDefault(d=> d.ID == documetToUpdate.ID)
        //
        //
        CopyUserInputData(documentToUpdate, doc); //You should implement this method that save user input in the given "doc" object!   
        context.SaveChanges();
        return true;
    }
}

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