Question

我无法使用EntityState.Modified更新我的某个模型，因为它还尝试更新我的导航属性（我没有更改）。我的控制器动作是：

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Rooms([Bind(Include = "ID,BedroomCount,BedroomsDescription,BathroomCount,BathroomsDescription")] Property property)
    {
        if (ModelState.IsValid)
        {
            //Modify property
            property.DateModified = DateTime.Now;
            property.Status = 1;
            db.Entry(property).State = EntityState.Modified;
            await db.SaveChangesAsync();
            return RedirectToAction("Index");
        }

        return View(property);
    }

我的模型看起来像是：

public class Property
{
    public int ID { get; set; }

    public Int16 BedroomCount { get; set; }

    public string BedroomsDescription { get; set; }

    public Int16 BathroomCount { get; set; }

    public string BathroomsDescription { get; set; }

    public int CommunityID { get; set; }

    public int PropertyTypeID { get; set; }

    public virtual Community Community { get; set; }
    public virtual PropertyType PropertyType { get; set; }
}

正如你所看到的，我从我的viewModel绑定了一堆东西（浴室和卧室等），但我没有修改导航属性＆＃39;社区＆＃39;根本没有，但每当我发布此动作方法时，我都会收到以下错误：

UPDATE语句与FOREIGN KEY约束冲突＆＃34; FK_dbo.Property_dbo.Community_CommunityID＆＃34 ;.冲突发生在数据库＆＃34; MyDatabase＆＃34;，表＆＃34; dbo.Community＆＃34;，列＆＃39; ID＆＃39;。该声明已被终止。

如果不尝试更新外键，我该如何更新此模型？我无法在任何地方找到答案

Answer 1

嗨，请你试一试，我希望它能奏效。

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Rooms([Bind(Include = "ID,BedroomCount,BedroomsDescription,BathroomCount,BathroomsDescription")] Property property)
{
    if (ModelState.IsValid)
    {
        // try this read this entoity from context and update properties you need to update
       var dbproperty = db.Property.FirstOrDefault(x=>x.Id= property.Id); // handle null 
        //Modify property
        dbproperty .DateModified = DateTime.Now;
        dbproperty .Status = 1;      

       // assuming in your context class Properties is the name of table.
         db.Entry(dbproperty ).State = EntityState.Modified;
        await db.SaveChangesAsync();
        return RedirectToAction("Index");
    }

    return View(property);
}

Answer 2

将导航属性的状态也设置为EntityState.Unchanged或EntityState.Modified。

或者，在db.Entry(property).State = EntityState.Modified;之前将nav属性设置为null。

EntityState.Modified不更新导航属性

2 个答案: