Hie, I'm having a bit of a crisis trying to run an sql query from a C# class. It was working fine in the Login page it was in before and I changed very little of it when I moved it over.
SQL query in class:
namespace Masca
{
public class loginc
{
// Telling the class that the page 'Login' exists.
public Login login;
....
public void Login ()
{
// connection parameters
string sqlcon = "datasource=localhost;port=3306;username = root; password = root";
//Command to carry out -This is what the exception highlights when it's thrown.
string query = "SELECT * FROM logon.login where username = '" + login.username.Text + "' and password = '" + login.password.Password + "';";
MySqlConnection con = new MySqlConnection(sqlcon);
MySqlCommand cmd = new MySqlCommand (query,con);
MySqlDataReader rdr;
con.Open();
rdr = cmd.ExecuteReader();
int count = 0;
while (rdr.Read())
{
count = count + 1;
}
if (count == 1)
{
//If the username and password match those in the database table, run the method 'login' in the login page cs.
login.login();
}
else
{
// if they don't match, run the method 'failLogin' in the login page cs.
login.failLogin();
}
}
In login.cs I have two textboxes and a button. One for the username and one for the password. The button is supposed to trigger the above code:
public void Logon_Click(object sender, RoutedEventArgs e)
{
loginc.Login();
}
Which it does fine. However I get the classic "Object reference not set to an instance of an object" exception thrown on the query. When I enter the actual credentials instead of '+ login.username.Text +' and '+ login.password.Password +' then the exception gets thrown on 'login.Login()'.
I don't understand why the loginc.cs class refuses to relate to the login.cs but the login.cs clearly has no problem triggering the method in class the same way. Anyone know where I'm going wrong?
