c# - SqlParameter和C#

大家好，有人可以帮我这个忙。我花了将近2天的时间来弄清楚这一点。

我在C＃中有一个此参数查询

UPDATE [User]
SET LoginName = '@LoginName', Name = '@Name',
    Surname = '@Surname', Telphone = '@Telphone',
    Cellphone = '@Cellphone', Fax = '@Fax', Email = '@Email',
    Password = '@Password', PasswordCreationDate = @PasswordCreationDate,
    IsActive = @IsActive, ManagerID = @ManagerID,
    SuperVisorID = @SuperVisorID, TeamLeaderID = @TeamLeaderID,
    PermissionID = @PermissionID
WHERE UserID = @UserID

我将此值分配给了@Telephone参数，但是失败了，所以我打开了SQL Server Profiler，我看到它给了我这个

USE Collector
exec sp_executesql N'UPDATE [User] SET LoginName=''@LoginName'', Name=''@Name'', Surname=''@Surname'',
Telphone=''@Telphone'',
 Cellphone=''@Cellphone'', Fax=''@Fax'',
Email=''@Email'', Password=''@Password'', PasswordCreationDate = @PasswordCreationDate,
IsActive = @IsActive, ManagerID = @ManagerID, SuperVisorID = @SuperVisorID,
TeamLeaderID = @TeamLeaderID, PermissionID = @PermissionID WHERE UserID = @UserID',
N'@UserID int,@LoginName nvarchar(6),@Name nvarchar(9),@Surname nvarchar(8),
@Telphone nvarchar(4000)
,@Cellphone nvarchar(4),@Fax nvarchar(3),@Email nvarchar(3),
@Password nvarchar(32),@PasswordCreationDate datetime,@IsActive bit,@ManagerID int,
@SuperVisorID int,@TeamLeaderID int,@PermissionID int',@UserID=29,@LoginName=N'daniel',
@Name=N'Daniel123',@Surname=N'asdfasdf',
@Telphone=DEFAULT,
@Cellphone=N'3453',@Fax=N'345',
@Email=N'adf',@Password=N'5F4DCC3B5AA765D61D8327DEB882CF99',
@PasswordCreationDate='2015-04-03 21:55:57',@IsActive=1,@ManagerID=7,@SuperVisorID=7,
@TeamLeaderID=7,@PermissionID=1

不用看这个查询，我什至认为它已经在其中放置了DEFAULT一词，甚至以为我已专门分配了''，所以它返回警告。


  参数化查询'（@UserID int，@ LoginName nvarchar（6），@Name nvarchar（9），@ Surname n'期望使用未提供的参数'@Telphone'。


但是我确实给它分配了一个new SqlParameter("@Telphone", "''");

我想念什么？我需要另一只眼睛，请帮忙。

表def：

USE [Collector]
GO

/****** Object:  Table [dbo].[User]    Script Date: 2015/04/11 08:19:09 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[User](
    [UserID] [int] IDENTITY(1,1) NOT NULL,
    [LoginName] [nvarchar](255) NOT NULL,
    [Name] [nvarchar](255) NOT NULL,
    [Surname] [nvarchar](255) NOT NULL,
    [Telphone] [nvarchar](50) NULL,
    [Cellphone] [nvarchar](50) NULL,
    [Fax] [nvarchar](50) NULL,
    [Email] [nvarchar](50) NULL,
    [Password] [nvarchar](255) NOT NULL,
    [PasswordCreationDate] [datetime] NOT NULL,
    [IsActive] [bit] NOT NULL CONSTRAINT [DF_User_IsActive]  DEFAULT ((1)),
    [ManagerID] [int] NULL,
    [SuperVisorID] [int] NULL,
    [TeamLeaderID] [int] NULL,
    [PermissionID] [int] NULL,
 CONSTRAINT [PK_User] PRIMARY KEY CLUSTERED
(
    [UserID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

感谢大家的关注。我设法找出问题所在

罪魁祸首..我不得不修改反射部分以检查它是否为字符串，而不使用默认值为null的值。

public static object GetDefaultValue(this Type type)
    {
        if (type == null) throw new ArgumentNullException("type");

        Expression<Func<object>> e = Expression.Lambda<Func<object>>(
            Expression.Convert(
            Expression.Default(type), typeof(object)
            )
        );

        // Compile and return the value.
        return e.Compile()();
    }

最佳答案

您不需要在参数中使用单引号。就像这样使用它们；

Telphone = @Telphone

对于单引号，sql将其视为string literal，而不是参数。

关于c# - SqlParameter和C#，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/29581131/