ASP.NET MVC 一对一关联数据未显示在索引页上

Question

我的情况是产品有一个库存。所以我在 Stocks 表上添加了 ProductId。表有这样的记录：

产品表：

标识 |姓名 |说明 |售价

----------------------------------- -

1 |产品1 |描述 | 10.20

2 |产品2 |产品描述 | 20.55

----------------------------------- -

库存表：

标识 |产品编号 |数量

----------------------------------- -

1 | 1 | 100

2 | 2 | 250

----------------------------------- -

现在在产品索引页面上，我想在 html 表上显示数据，如下所示：

<table border="1">
  <tr>
    <th>Name</th>
    <th>Description</th>
    <th>Selling Price</th>
    <th>Stock</th>
  </tr>
  <tr>
    <td>product1</td>
    <td>desc</td>
    <td>10.20</td>
    <td>100 (Note: I cannot see stock data when i open products index, this is what i want to see)</td>
  </tr>
  <tr>
    <td>product2</td>
    <td>product desc</td>
    <td>20.55</td>
    <td>250 (Note: I cannot see stock data when i open products index, this is what i want to see)</td>
  </tr>
</table>

下面是我到目前为止所做的MVC代码：

public class Product
{
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Description { get; set; }
    public Decimal SellingPrice { get; set; }

    public virtual Stock Stock { get; set; }
}



 public class Stock
{
    public int Id { get; set; }
    public int Qty { get; set; }
    public int ProductId { get; set; }
    [Required]
    public virtual Product Product { get; set; }
}

  // GET: Products
    public ActionResult Index()
    {
        var products = db.Products.ToList();
        return View(products);
    }

<table class="table">
<tr>
    <th>
        @Html.DisplayNameFor(model => model.Name)
    </th>
    <th>
        @Html.DisplayNameFor(model => model.Description)
    </th>
    <th>
        @Html.DisplayNameFor(model => model.SellingPrice)
    </th>
    <th>@Html.DisplayNameFor(model => model.Stock)</th>
    <th></th>
</tr>

@foreach (var item in Model)
{
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Name)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Description)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.SellingPrice)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Stock.Qty)
        </td>
            <td>
                @Html.ActionLink("Edit", "Edit", new { id = item.Id }) |
                @Html.ActionLink("Details", "Details", new { id = item.Id }) |
                @Html.ActionLink("Delete", "Delete", new { id = item.Id })
            </td>
            </tr>
}

@Html.DisplayFor(modelItem => item.Stock.Qty 这段特定的代码没有返回任何记录，这就是为什么我在产品索引页面上看不到库存数据。任何帮助将不胜感激，谢谢！

这里是附件，sql生成表的截图

Products table

Stocks table

Answer 1

您需要在查询中添加此内容：

//Don't forget to add this on your using statements
using System.Data.Entity;

var products = db.Products.Include(x=>x.Stock).ToList();

您需要此 Include 扩展方法，以便它与您的查询表建立第一级关系。

同时更新您的模型，以包含您的 Stock 模型的 ID：

public class Product
{
public int Id { get; set; }
[Required]
public string Name { get; set; }
[Required]
public string Description { get; set; }
public Decimal SellingPrice { get; set; }

public virtual int StockID {get;set;} //Add this
public virtual Stock Stock { get; set; }
}

别忘了用你的模型更新你的数据库。