数据读取器与指定的不兼容。在数据读取器中没有具有相同名称的对应列

Question

我不断收到以下异常。例外使我感到困惑，因为我没有选择UserID。

我尝试将选择更改为，SELECT *但这只会导致a result.Count为0，无论数据是否存在。

我在数据库中有一个虚拟记录，称为bob tob。

我注意到，如果将鼠标悬停在的用户部分上db.Users.SqlQuery。

里面的文字是

{SELECT 
[Extent1].[userID] AS [userID], 
[Extent1].[userFirstName] AS [userFirstName], 
[Extent1].[userLastName] AS [userLastName], 
[Extent1].[userName] AS [userName], 
[Extent1].[userEmail] AS [userEmail], 
[Extent1].[userPassword] AS [userPassword], 
[Extent1].[userStatus] AS [userStatus], 
[Extent1].[userEmailVerificationStatus] AS [userEmailVerificationStatus], 
[Extent1].[userActivationCode] AS [userActivationCode]
FROM [dbo].[Users] AS [Extent1]}

我猜它正在尝试选择所有User类项，无论如何？如果是这样，那我该如何制止呢？我想念什么？

这是例外：

数据读取器与指定的“ UserRegistrationPasswordsModel.User”不兼容。类型“ userID”的成员在数据读取器中没有具有相同名称的对应列。

下面是调用的代码EmailExists。我ToString()错误地希望这可能是问题所在。

#region EmailExist
// Email already exists?
if (Utilities.EmailExists(user.userEmail.ToString()))
{
    // A pretty awesome way to make a custom exception
    ModelState.AddModelError("EmailExist", "Email already exists");

    // Bounce back
    return View(user);
}
#endregion

下面是检查电子邮件是否存在的过程。

#region EmailExists
    // Confirm if the Email exists or not
    public static bool EmailExists(string Email)
    {
        bool result = false;
        Models.UserRegistrationPasswordsEntities1 db = new Models.UserRegistrationPasswordsEntities1();
        var queryResult = db.Users.SqlQuery("SELECT userEmail FROM Users WHERE userEmail = @1;", 
                                                                          new SqlParameter("@1", Email)).FirstOrDefault();

        // the ternary opertor is pretty awesome
        result = queryResult.Result.GetType() == null ? false : true;

        return result;
    }
    #endregion

这是表结构：

CREATE TABLE [dbo].[Users]
(
    [userID]                      INT              IDENTITY (1, 1) NOT NULL,
    [userFirstName]               VARCHAR (50)     NOT NULL,
    [userLastName]                VARCHAR (50)     NOT NULL,
    [userName]                    VARCHAR (50)     NOT NULL,
    [userEmail]                   VARCHAR (50)     NOT NULL,
    [userPassword]                VARCHAR (100)    NOT NULL,
    [userStatus]                  BIT              DEFAULT ((0)) NOT NULL,
    [userEmailVerificationStatus] BIT              DEFAULT ((0)) NOT NULL,
    [userActivationCode]          UNIQUEIDENTIFIER DEFAULT (newid()) NOT NULL,
    [userDateOfBirth]             DATETIME         NOT NULL,

    PRIMARY KEY CLUSTERED ([userID] ASC)
);

这是User模型类：

public partial class User
{
    public int userID { get; set; }

    [Display(Name = "First Name")]
    [DataType(DataType.Text)]
    [Required(AllowEmptyStrings = false, ErrorMessage ="First name required")]
    public string userFirstName { get; set; }

    [Display(Name = "Last Name")]
    [DataType(DataType.Text)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Last name required")]
    public string userLastName { get; set; }

    [Display(Name = "Username")]
    [DataType(DataType.Text)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Username required")]
    public string userName { get; set; }

    [Display(Name = "Email")]
    [DataType(DataType.EmailAddress)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "email is required")]
    public string userEmail { get; set; }

    [Display(Name = "Date Of Birth")]
    [DataType(DataType.DateTime)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Date of Birth is required")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime userDateOfBirth { get; set;}


    [Display(Name = "Password")]
    [DataType(DataType.Password)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Password is required")]
    [MinLength(6, ErrorMessage = "Minimum of 6 characters required")]
    public string userPassword { get; set; }

    [Display(Name = "Confirm Password")]
    [DataType(DataType.Password)]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Confirm password is required")]
    [Compare("userPassword", ErrorMessage = "Confirm password and password do not match")]
    public string userConfirmPassword { get; set; }

    public bool userStatus { get; set; }
    public bool userEmailVerificationStatus { get; set; }

    public System.Guid userActivationCode { get; set; }
}

我花了2个小时的大部分时间来解决这个问题。

以下是我为寻求解决方案而访问的资源。

任何和所有帮助表示赞赏。

https://docs.microsoft.com/zh-cn/aspnet/mvc/overview/getting-started/getting-started-with-ef-using-mvc/advanced-entity-framework-scenarios-for-an-mvc- Web应用程序

https://forums.asp.net/t/1991176.aspx?+数据+阅读器+与+指定模型是否兼容

EF映射的对象不兼容的数据读取器异常

数据读取器与指定的实体框架不兼容

https://forums.asp.net/t/1980259.aspx？ +类型+考勤ID +没有+没有+一个+相应的+列+数据+阅读器+带有+相同+名称+

什么会导致EntityCommandDefinition.ExecuteStoreCommands中的EntityCommandExecutionException？

Answer 1

错误提示：

类型“ userID”的成员在数据读取器中没有具有相同名称的对应列。

这意味着您的查询返回的结果与您的实体（User）的类型不匹配。的确确实没有，您的查询只返回一列userEmail，而类型则User包含更多列（包括userID错误消息中提到的列）。为什么结果应该匹配类型User？因为您正在通过查询此实体db.Users.SqlQuery。

您的查询也是错误的（因为'@1'不是参数而是文字字符串），但这没关系，因为无论如何您都不需要使用原始sql查询。做就是了：

public static bool EmailExists(string Email)
{        
    using (var db = new Models.UserRegistrationPasswordsEntities1()) {
        return db.Users.Any(c => c.userEmail == Email);
    }       
}

如果要发出任意的sql查询（尽管我应该再说一遍，在这种情况下绝对没有理由这样做）-使用db.Database.SqlQuery：

using (var db = new Models.UserRegistrationPasswordsEntities1()) {
    var email = db.Database.SqlQuery<string>(
        "SELECT userEmail FROM Users WHERE userEmail = @email",
        new SqlParameter("email", Email))
    .FirstOrDefault();
    ...
}