Question

I try to autentificate to a database, to create a Login function. Every time I press the button I receive this error: System.InvalidOperationException: The connection is not open. at MySql.Data.MySqlClient.MySqlConnection.Throw(Exception ex) at MySql.Data.MySqlClient.MySqlCommand.Throw(Exception ex) at MySql.Data.MySqlClient.MySqlCommand.Prepare() at start.CheckUserLogin(String username, String password) in c:\Users\RARES\Documents\Visual Studio 2010\WebSites\tem1\start.aspx.cs:line 46

Please tell me how can I read the data and check if the user and pass are the same as the ThextBox texts.

protected void Button1_Click(object sender, EventArgs e)
{
    try
    {
        String sCon = "SERVER=localhost;DATABASE=sd_tema1;UID=root;";
        MySqlConnection con = new MySqlConnection(sCon);

        if (CheckUserLogin(Label2.Text, Label3.Text))
        {
            Response.Redirect("login.aspx");
        } 

    }
    catch (Exception ex)
    {
        Label1.Text = ex.ToString();
    }
}

public Boolean CheckUserLogin(string username, string password)
{
    try
    {
        String sCon = "SERVER=localhost;DATABASE=sd_tema1;UID=root;";
        MySqlConnection con = new MySqlConnection(sCon);

        String query = "Select * from users where username= ?userName and password= ?passWord";
        MySqlCommand cmd = new MySqlCommand(query,con);
        cmd.Parameters.Add("?userName", TextBox1.Text);
        cmd.Parameters.Add("?passWord", TextBox2.Text);
        cmd.Prepare();
        MySqlDataReader print = cmd.ExecuteReader();
        bool read = print.Read();
        if(username.Equals(print.GetString("1")) && password.Equals(print.GetString("2"))) return true;
    }
    catch (Exception ex)
    {
        Label1.Text = ex.ToString();
    }
    return false;
}

Answer 1

You didn’t open the connection before calling ExecuteReader method. Call con.Open. Your issue will be resolved.