使用MVC和实体框架查看数据库中的数据

Question

I am trying to view list of items from database ( I am using Entity Framework).

My Repository method:

public List<string> getListOfItems(int i)
{
    return (from x in db.Items where x.ID == i select x.Text).ToList();
}

My Controller:

public ActionResult Index()
{
    var itemOutput = repo.getListOfItems(1); // I just put 1 since I didn't know how to specify "i" - However theoretically it should return first item in database but its not
    ViewBag.itemOutput = itemOutput ;

    return View();
}

Model:

public class items
{
    [Key]
    public int ID{ get; set; }
    public string name{ get; set; }
    public string quantity{ get; set; }
}

ItemModel:

public class itemModels
{ 
    public List<List<string>> itemData{ get; set; }
}

View:

@foreach (var item in ViewBag.itemOutput )
{
    <table id="t01">
        <tr>
            <td>@item.name</td>
        </tr>
    </table>
}

Answer 1

Answer:

ViewBag.itemOutput is a List<string> which makes item a string .

Therefore, use @item instead of @item.name (as string does not have .name property) in your view:

@foreach (var item in ViewBag.itemOutput )
{
    <table id="t01">
        <tr>
            <td>@item</td>
        </tr>
    </table>
}

Also, to get the full list, you could do:

public List<string> getListOfItems()
{
    return (from x in db.Items select x.Text).ToList();
}

And then just call getListOfItems() with no param.

---

Random comments:

1) Don't use plural for class name, unless the class is somewhat a collection of things

--> public class item // without s

2) You said in comments that items are full varchar which is untrue as per your class definition (you have ID , name & quantity ).

3) Using string for quantity is a bit weird.

4) You could indeed change your getListOfItems method to:

public List<item> getListOfItems()
{
    return (from x in db.Items select x).ToList();
    // which can be simplified to:
    // return db.Items.ToList();
}

but you should then change your view back to @item.name .

This would however allow you to do:

@foreach (var item in ViewBag.itemOutput )
{
    <table id="t01">
        <tr>
            <td>@item.name</td>
            <td>@item.quantity</td>
        </tr>
    </table>
}

5) You have an ItemModel but you are not using it. You could modify it and use it instead of the ViewBag .

Answer 2

getListOfItems() returns a list of string, but you're referring to an actual object in ViewBag.itemOutput

Instead of select x.Text do a select x, and make the return value List<items>

public List<items> getListOfItems(int i)
{
    return (from x in db.Items where x.ID == i select x).ToList();
}

Then you can keep your razor template the same to refer to @item.name