使用 Postal 创建的电子邮件包含数据库查询而不是字符串值

Question

在我的应用程序中，您可以将任务 (TaskDetails) 分配给一个人 (Employee)，然后这个人会在从包含任务标题的数据库中提取的 his/her 电子邮件地址上收到一封电子邮件通知。我为此使用邮政。

我在 TaskDetails 的 Create 方法中添加了：

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(TaskDetails taskDetails)
{
    if (ModelState.IsValid)
    {
        db.Tasks.Add(taskDetails);
        db.SaveChanges();
        //Extra code for email notification to Employee when new Task is created
        //See: http://aboutcode.net/postal
        var emplName =   from e in db.Employees
                        where e.EmployeeId.Equals(taskDetails.EmployeeId)
                       select e.FirstName;
        try
        {
            var email = new NewTaskEmail
            {
                ToEmail = "testio@testing.com"
                ToFirstname = emplName.toString()
            };
            email.Send();
        }
        catch (Exception ex)
        {
            return View("Error", new HandleErrorInfo(ex, "TaskDetails", "Create"));
        }
        //end of extra code for email notification
        return RedirectToAction("Index");
    }
//some viewbag code
    return View(taskDetails);
}

我的电子邮件视图：

@model MyApp.Models.NewTaskEmail

From: mailer@example.com
To: @Model.ToEmail
Subject: You have a new task 

Hi @Model.ToFirstname,
//rest of email body

调试时我可以看到 ToEmail 和 ToFirstname 的值正确，但这是生成的电子邮件：

X-Sender: mailer@example.com
X-Receiver: testio@testing.com
MIME-Version: 1.0
From: mailer@example.com
To: testio@testing.com
Date: 12 Apr 2017 21:11:33 +0200
Subject: You have a new task
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable

Hi SELECT =0D=0A    [Extent1].[FirstName] AS [FirstName]=0D=0A   =
 FROM [dbo].[Employee] AS [Extent1]=0D=0A    WHERE [Extent1].[Emp=
loyeeId] =3D @p__linq__0,=0D=0A=0D=0A

硬编码字符串被正确识别，但数据库查询 (Employee.FirstName) 产生的字符串显示为查询本身。我做错了什么？

Answer 1

var emplName = from e in db.Employees
   where e.EmployeeId.Equals(taskDetails.EmployeeId)
   select e.FirstName;

emplName是字符串的集合，所以需要用到FirstOrDefault()

var emplName = (from e in db.Employees
   where e.EmployeeId == taskDetails.EmployeeId
   select e.FirstName).FirstOrDefault();

使用 Postal 创建的电子邮件包含数据库查询而不是字符串值

Email created with Postal contains database query instead of string value

linq

asp.net-mvc

postal