Linq查询没有返回值

我目前有2 dbContexts，我不确定这是否有所不同。ApplicationDbContext和CompanyDBContext。这些表已经在数据库中设置好了，我已经在companydetails表中添加了数据。

我可能对我的代码有几个问题，我不确定我在关于companyID的视图中做了什么是正确的，但主要是我的问题是我不确定为什么我的linq查询在我的表中有数据时不返回任何结果。

My CompanyDBContext goes as is

public class CompanyDBContext : DbContext
{
    public DbSet<CompanyDetails> companies { get; set; }
}

这是我的模型

public class CompanyDetails
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int? companyID { get; set; }
    [Display(Name = "Company Name")]
    public string CompanyName { get; set; }
}

我已经写了一个linq查询，它应该已经得到了我放入数据库的一行。使用这个linq查询，我构造了一个SelectListItems列表，并将其传递给viewbag，然后我希望能够有一个包含公司名称的下拉框，用户可以在其中进行选择。

 public ActionResult Register()
    {
        //var regViewModel = new RegisterViewModel();
        List<SelectListItem> companyList = null;
        using(var companies = new CompanyDBContext())
        {
            var companyNamesQuery = (from comp in companies.companies
                                     select new SelectListItem
                                     {
                                         Text = comp.CompanyName,
                                         Value = comp.companyID.ToString()
                                     });
            companyList = companyNamesQuery.ToList();
            @ViewBag.companies = companyList;
        }
        return View();
    }

这是视图，

    @using (Html.BeginForm("Register", "Account", FormMethod.Post, new { @class = "form-horizontal", role = "form" }))
{
    @Html.AntiForgeryToken()
    <h4>Create a new account.</h4>
    <hr />
    @Html.ValidationSummary("", new { @class = "text-danger" })
    <div class="form-group">
        @Html.LabelFor(m => m.Email, new { @class = "col-md-2 control-label" })
        <div class="col-md-10">
            @Html.TextBoxFor(m => m.Email, new { @class = "form-control" })
        </div>
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.userCompanyID, new { @class = "col-md-2 control-label" })
        <div class="col-md-10">
            @Html.DropDownListFor(m => m.userCompanyID, new SelectList(ViewBag.companies, "companyID", "CompanyName"))
        </div>
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Password, new { @class = "col-md-2 control-label" })
        <div class="col-md-10">
            @Html.PasswordFor(m => m.Password, new { @class = "form-control" })
        </div>
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.ConfirmPassword, new { @class = "col-md-2 control-label" })
        <div class="col-md-10">
            @Html.PasswordFor(m => m.ConfirmPassword, new { @class = "form-control" })
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" class="btn btn-default" value="Register" />
        </div>
    </div>
}

这是我的连接字符串

    <add name="DefaultConnection" connectionString="Data Source=xxxxxx'SQLEXPRESS;Initial Catalog=DBTest;User ID=x;Password=Xxxxx1;Persist Security Info=False;" providerName="System.Data.SqlClient" />
<add name="DevConnection" connectionString="Data Source=xxxxxx'SQLEXPRESS;Initial Catalog=DBTest;User ID=x;Password=Xxxxx1;Persist Security Info=False;" providerName="System.Data.SqlClient" />

@Html.DropDownListFor(m => m.userCompanyID, new SelectList(ViewBag.companies, "companyID", "CompanyName"))

var companyNamesQuery = (from comp in companies.companies
                                 select new SelectListItem
                                 {
                                     Text = comp.CompanyName,
                                     Value = comp.companyID.ToString()
                                 });

@Html.DropDownListFor(m => m.userCompanyID, new SelectList(ViewBag.companies, "Value", "Text"))