Question

我有两个名为Category和Ticket的表，我想使用已经在我的数据库中的这两个表来制作我的统计表。

我已成功制作了“类别”列，但我不知道如何使我的“已发票”列工作。

My Ticket Issued列基本上将所有门票分类到各自的类别并计算它。

我需要HomeController中的帮助编码，因此我可以将两个表中的CategoryID和两个表中的一些相关联，并在About.cshtml中稍微链接以在About页面上显示该表。

HomeController.cs＆lt; - 需要在这里修改代码

public ActionResult About()
{
    var data = from category in db.Categories
               group category by category.Title into categoryGroup
               select new CategoryGroup()
               {
                   Title = categoryGroup.Key,
                   CategoryCount = categoryGroup.Count() <-- ***This needs to change into Count of Tickets which have the same category ID***
               };
    return View(data);
}

的ViewModels \ CategoryGroup

public class CategoryGroup
    {
        public int CategoryID { get; set; }
        public int CategoryCount { get; set; }
        public string Title { get; set; }
    }

About.cshtml

@model IEnumerable<RecreationalServicesTicketingSystem.ViewModels.CategoryGroup>

@{
    ViewBag.Title = "Ticket Statistics";
}

<h2>Ticket Category Statistics</h2>

<table>
    <tr>
        <th>
            Category
        </th>
        <th>
            Tickets Issued
        </th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Title)         
        </td>
        <td>
            @item.CategoryCount @*Instead of Category Count I want numbers of tickets that have been issued for certain IDs. *@
        </td>
    </tr>
}
</table>

仅供参考

门票类

public enum Priority
    {
        Low,Med,High
    }

public class Ticket
{
    public int TicketID { get; set; }
    public int CategoryID { get; set; }
    public int UserID { get; set; }
    public string Issue { get; set; } //A line for our issue like enrollment date in student
    public Priority? Priority { get; set; }

    public virtual Category Category { get; set; }
    public virtual User User { get; set; }
}

类别类

public class Category
{
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int CategoryID { get; set; }
    public string Title { get; set; }

    public virtual ICollection<Ticket> Tickets { get; set; }
}

Answer 1

var data = from category in db.Categories
           select new CategoryGroup()
           {
               CategoryID = category.CategoryID,
               Title = category.Title,
               CategoryCount = category.Tickets.Count()
           };

MVC5 SQL LEFT JOIN QUERY

1 个答案: