Expire Mysql user time

Question

I’m making a system of login in C# where the login user will be verified his login, password and the time left to use the system. Until the login and password check part I managed to do, but I’m having trouble checking the usage time. For example, it cannot use when a certain date arrives.

Follow my code here:

try
{
    string sql = "SELECT * FROM users WHERE userName = @login AND userPass  = @senha ";

    MySqlConnection con = new MySqlConnection("host=; user=; password=; database=; Port=3306;");
    MySqlCommand cmd = new MySqlCommand(sql, con);

    cmd.Parameters.AddWithValue("@login", this.usuario.Text);
    cmd.Parameters.AddWithValue("@senha", this.senha.Text);

    con.Open();

    int a = (int)cmd.ExecuteScalar();

    if (a > 0)// caso login e senha e tempo de uso OK
    {
        Form1 segundo = new Form1();
        this.Hide();
        segundo.ShowDialog();
    }
    else
    {
        MessageBox.Show("Seu tempo de uso acabou");
    }

}
catch 
{
    MessageBox.Show("User or Pass Incorrect!");
    usuario.Text = "";
    senha.Text = "";
}

In my bank I have the following fields: userid, username, userPass, Dateexpiration

Simulating a situation, the user was registered today and can only log in until the day 25/02/2017. I want the day 26/02/2017 he can no longer login.

Answer 1

Keeping the logic of your implementation, you can declare your SQL statement like this:

string sql = "SELECT * FROM users WHERE userName = @login AND userPass  = @senha AND DateExpiration >= DATE(@dataAtual)";

And "sign" the parameters like this:

cmd.Parameters.AddWithValue("@login", this.usuario.Text);
cmd.Parameters.AddWithValue("@senha", this.senha.Text);
cmd.Parameters.AddWithValue("@dataAtual", DateTime.Today);