C# 在构造函数和初始值设定项中，LINQ只支持属性或字段参数绑定到实体。Linq中的ViewModel 您也可以表示数据库表结构。.cat.name后面是否应该有逗号？您是否尝试了所提供的SO链接中的第二种解决方案？发布TicketViewModel（以及任何

在构造函数和初始值设定项中，LINQ只支持属性或字段参数绑定到实体。Linq中的ViewModel

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您也可以表示数据库表结构。.cat.name后面是否应该有逗号？您是否尝试了所提供的SO链接中的第二种解决方案？发布

TicketViewModel

（以及任何继承的类）的定义。

TicketViewModel/TicketModel

的构造函数或属性设置器中是否有其他代码？

public List<TicketViewModel> GetTickets()
{
    DBEntities db = new DBEntities();

    List<TicketViewModel> tickets =
        (from ticket in db.Tickets
            join user in db.AspNetUsers on ticket.user_id equals user.Id
            join cat in db.TicketCategories on ticket.sub_category_id equals cat.id
            where ticket.is_active == true
            select new TicketViewModel
            {
                username = user.UserName,
                id = ticket.id,
                subject = ticket.subject,
                message = ticket.message,
                user_id = ticket.user_id,
                priority = (int)ticket.priority,
                date_created = ticket.date_created,
                date_modified = ticket.date_modified,
                assigned_to = ticket.assigned_to,
                is_active = ticket.is_active,
                sub_category_id = (int)ticket.sub_category_id,
                attatchments = ticket.attatchments,
                ticket_type = cat.name,
            }).ToList();

    return tickets;
} 

public class TicketViewModel
{

    private DBEntities db = new DBEntities();

    [DisplayName("Ticket ID")]
    public int id { get; set; }

    [DisplayName("User ID")]
    public string user_id { get; set; }

    [DisplayName("Username")]
    public string username { get; set; }

    [DisplayName("Subject")]
    [Required(ErrorMessage = "required")]
    public string subject { get; set; }

    [DisplayName("Message")]
    [Required(ErrorMessage = "required")]
    public string message { get; set; }

    [DisplayName("Active")]
    public bool is_active { get; set; }

    [DisplayName("Date Created")]
    public DateTime date_created { get; set; }

    [DisplayName("Date Modified")]
    public DateTime date_modified { get; set; }

    [DisplayName("Category")]
    public int sub_category_id { get; set; }

    [DisplayName("Assigned To")]
    public string assigned_to { get; set; }

    [DisplayName("Attatchments")]
    public string attatchments { get; set; }

    [DisplayName("Priority")]
    public int priority { get; set; }

    public List<Attatchment> _attatchments = new List<Attatchment>();

    public string ticket_type = "";

    public int comments = 0;

    public List<SelectListItem> PrioritySelection = new List<SelectListItem>(){
        new SelectListItem(){Value = "1", Text = "Low"},
        new SelectListItem(){Value = "2", Text = "Medium"},
        new SelectListItem(){Value = "3", Text = "High"}
    };
}