"使用SQLConnection对用户"C#登录失败

Question

我一直在尝试通过我的C#代码连接到我的数据库(与我的代码位于同一台计算机上).问题是我一直得到"登录失败的用户"""错误...我承认我对连接数据库的知识很少,我已经尝试了其他问题中的几乎所有步骤!

这是我的代码的一部分:

SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["SQLServerConnection"].ConnectionString);
        SqlCommand command = connection.CreateCommand();
        command.CommandText = @"IF EXISTS
                            (
                              SELECT *
                              FROM user 
                              WHERE EMAILADRES = @email and WACHTWOORD = @password
                            ) SELECT CAST (1 as bit) 
                            ELSE
                              SELECT CAST(0 as bit)";
        command.Parameters.AddWithValue("email", email);
        command.Parameters.AddWithValue("password", password);


        connection.Open();
        object ReturnBool = command.ExecuteScalar();
        connection.Close();

这是我的连接字符串:

<add name="SQLServerConnection" connectionString="Server=localhost; Database=database1;uid=NT AUTHORITY\NETWORK SERVICE" />

Answer 1

你需要改变连接字符串;

<add name="SQLServerConnection" connectionString="Server=localhost;Database=database1;Trusted_Connection=True;/>

如果您使用Windows身份验证连接到本地数据库,则需要设置Trusted_Connection=True; 如果您使用的是SQL Server身份验证,则需要声明User Id=myUsername; Password=myPassword;.

Answer 2

我建议这样做:

1)将连接字符串更改为:

<add name="SQLServerConnection" connectionString="Server=.;Database=database1;Trusted_Connection=True;"/>

'服务器='. - 使用计算机上的默认SQL Server实例,

'Trusted_Connection = True' - Windows身份验证用于验证您对SQL Server实例的访问权限.

2)签入Sql Management Studio是您的Windows用户有权访问'database1'.

你得到的第二个错误,因为你应该在参数名称中添加'@',如下所示:

command.Parameters.AddWithValue("@email", email);
command.Parameters.AddWithValue("@password", password);

我还建议你改变你的代码:

using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings["SQLServerConnection"].ConnectionString))
{
    using (var command = connection.CreateCommand())
    {
        command.CommandText = @"IF EXISTS
                        (
                          SELECT *
                          FROM user 
                          WHERE EMAILADRES = @email and WACHTWOORD = @password
                        ) SELECT CAST (1 as bit) 
                        ELSE
                          SELECT CAST(0 as bit)";

        command.Parameters.AddWithValue("@email", email);
        command.Parameters.AddWithValue("@password", password);

        connection.Open();
        var result = command.ExecuteScalar();
    }
}