c# - 表没有得到更新，当使用 executeNonquery

Question

我正在尝试更改用户密码。我无法更新密码 :(。我收到的消息是密码已更改，因为它没有更改。。我的代码如下。如果有人可以建议我哪里出错了，请。我只是一个初学者...

protected void Button1_Click(object sender, EventArgs e)
{
    DatabaseLayer data = new DatabaseLayer();

    string username = Session["Authenticate"].ToString();
    string password = TextBox1.Text;
    string newpass = TextBox2.Text;
    string confirm = TextBox3.Text;
    string flag = "";

    if (newpass.ToString() == confirm.ToString())
    {
        flag = data.passwordChange(username, password, newpass);
        Literal1.Text = flag.ToString();
    }
    else
    {
        Literal1.Text = "New Password does not match the Confirm Password ";
    }
}

上面的点击事件必须修改我的密码，函数passwordChange如下..

public string passwordChange(string username, string password, string newPasswd)
{
    string SQLQuery = "SELECT password FROM LoginAccount WHERE username = '" + username + "'";
    string SQLQuery1 = "UPDATE LoginAccount SET password = ' " + newPasswd + " ' WHERE username = ' " + username + "'";
    SqlCommand command = new SqlCommand(SQLQuery, sqlConnection);
    SqlCommand command1 = new SqlCommand(SQLQuery1, sqlConnection);

    sqlConnection.Open();
    string sqlPassword = "";
    SqlDataReader reader;

    try
    {
        reader = command.ExecuteReader();


        if (reader.Read())
        {
            if (!reader.IsDBNull(0))
            {
                sqlPassword = reader["password"].ToString();
            }
        }
        reader.Close();

        if (sqlPassword.ToString() == password.ToString())
        {
            try
            {
                int flag = 0;
                flag = command1.ExecuteNonQuery();

                if (flag > 0)
                {
                    sqlConnection.Close();
                    return "Password Changed Successfully";
                }
                else
                {
                    sqlConnection.Close();
                    return "User Password could not be changed";
                }
            }
            catch (Exception exr)
            {
                sqlConnection.Close();
                return "Password Could Not Be Changed Please Try Again";
            }
        }
        else
        {
            sqlConnection.Close();
            return "User Password does not Match";
        }
    }
    catch (Exception exr)
    {
        sqlConnection.Close();
        return "User's Password already exists";
    }
}

我在附近放了一个断点

if(flag>0)

它仍然显示 executeNonquery 没有返回更新的行值，而且在 SQL Server 的后端，它没有改变，如果有人可以纠正我，请...我应该使用其他执行命令还是什么？我正在使用 VS 2008 和 SQL Server 2005 执行此操作..

Answer 1

1:这是单引号和双引号之间的间距:(如:' "+ username + "')
2) 你在乞求 SQL 注入(inject)。

在您的 PasswordChange 方法中试试这个:

public string PasswordChange(string userName, string oldPass, string newPass)
{
    using(SqlConnection sqlConnection = new SqlConnection(
        ConfigurationManager.ConnectionStrings["LoginDb"].ConnectionString))
   {
    string sqlToConfirmOldPass =
      "SELECT password FROM LoginAccount WHERE username = @userName";
    string sqlToUpdatePassword =
      "UPDATE LoginAccount SET password = @newPass WHERE username = @userName";

    SqlCommand confirmOldPass = new SqlCommand(sqlToConfirmOldPass, sqlConnection);
    confirmOldPass.Parameters.AddWithValue("@userName", userName);

    SqlCommand updatePassword = new SqlCommand(sqlToUpdatePassword, sqlConnection);
    updatePassword.Parameters.AddWithValue("@newPass", newPass);
    updatePassword.Parameters.AddWithValue("@userName", userName);

    [Rest of your code goes here]
   }
}

我也没有看到您在哪里设置 SqlConnection，所以我为此添加了一行。您需要根据需要对其进行修改。