Question

我在当前会话中将查询保存到本地数据库时遇到问题。但是，当我关闭应用程序时，数据库已更新。

场景：我有一个登录窗口和注册窗口，当用户注册我有查询将他/她的信息保存到数据库但是在关闭整个应用程序后，它应该将它保存在同一个会话中无需关闭应用程序。

我正在使用此代码进行注册窗口：

private async void button_Click(object sender, RoutedEventArgs e)
{
    if (textBox.Text.Length >= 4 && textBox1.Password.Length >= 4)
    {
        using (var conn = new SqlConnection(@"Data Source"))
        using (var cmd = conn.CreateCommand())
        {
            cmd.CommandText =
                 "Select Count(*) From Results Where PlayerName = @playerName";
            conn.Open();
            cmd.Parameters?.Add("@playerName", textBox.Text);
            cmd.Parameters?.Add("@Password", textBox1.Password);

            var count = (int) cmd.ExecuteScalar();

            if (count == 0)
            {
               cmd.CommandText =
                  "INSERT INTO LoginInfo (PlayerName, Password) Values (@playerName , @Password)";
               cmd.ExecuteNonQuery();
               conn.Close();
               Close();
            }
            else
            {
                label3.Content = "The UserName is already registerd!";
            }
         }
     }
     else
     {
        label3.Content =
                "Please Enter Valid information User Name +" +
                "and Password should be more than 4 Digits";
     }
}

编辑：我使用@displayName，建议，我看到实际上它已更新，因为当我写相同的信息时，它会让用户已经注册。 Linq to SQL login window中可能存在错误，这是我的登录窗口代码：

 private void Login_Click(object sender, RoutedEventArgs e)
 {
        var db = new DataClasses1DataContext();
        var userName = from t in db.LoginInfos
            select new
            {
                t.Id,
                t.PlayerName,
                t.Password
            };

        foreach (var variable in userName)
        {
            if (UserName.Text == variable.PlayerName && text_Password.Password == variable.Password)
            {
                var openChoiceGame = new ChoiceGame(UserName.Text);
                textBlock.Text = "The login information are correct ";
                openChoiceGame.Show();

                using (
                    var conn =
                        new SqlConnection(
                            @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Saif-DevEnv\Source\Workspaces\QuizClashGame\GameQuizClash\Players.mdf;Integrated Security=True;Connect Timeout=30")
                    )
                using (var cmd = conn.CreateCommand())
                {
                    cmd.CommandText = "Select Count(*) From Results Where PlayerName = @playerName";
                    cmd.Parameters.Add("@playerName", UserName.Text);
                    conn.Open();

                    var count = (int) cmd.ExecuteScalar();

                    if (count == 0)
                    {
                        // It means it does not exist.
                        cmd.CommandText = "INSERT INTO Results(PlayerName) VALUES (@playerName)";
                        cmd.ExecuteNonQuery();
                    }

                    conn.Close();
                    var player = new SoundPlayer(@"C:\Users\Saif-DevEnv\Desktop\SoundRes\switch32.wav");
                    player.Play();
                }

                Close();
            }
            else
            {
                textBlock.Text = "The login information are not correct ";
            }
        }
    }

登录窗口代码是否有任何错误？

Answer 1

首先想到：我看到Results上的ExecutingScalar（）在LoginInfo上的ExecutingNonQuery（），即在两个不同的表上。这是问题吗？

第二个想法：您可以更改插入LoginInfo的测试方式。这样做是相反的 -

if (cmd.ExecuteNonQuery() == -1)
{
    label3.Content = "The UserName is already registerd!";
}

Answer 2

我没有看到async关键字的任何原因。删除后它应该可以正常工作。

Answer 3

也许这会有所帮助：Asynchronous Programming

Answer 4

问题在于$i = 0; while($row = mysqli_fetch_array($res)){ array_push($result[$i], ($row[0] . $row[1] . $row[2] . $row[3] . $row[4] . $row[5])); $i++; }部分。但是，我的解决方案是将数据源添加到Linq To Sql或我的代码中DataContext(@DataSource)，并使用DataClasses1DataContext(@DataSource);方法Refresh

在关闭应用程序之前，SQL Server数据库不会保存新查询

4 个答案: