My SQl Query Error

Question

I have stored userid and password in mysql database, this query is showing login successfully for not stored data, so please correct it

string query = "select * from login where userid=@userid and password=@Lee ";
using (MySqlCommand cmd = new MySqlCommand(query))
{
cmd.Parameters.AddWithValue("@userid", id);
cmd.Parameters.AddWithValue("@Lee ", password);
cmd.Connection = cnn;
cnn.Open();
cmd.ExecuteNonQuery();
DialogResult dr = MessageBox.Show("Are you sure to Login now?", "Confirmation Message", MessageBoxButtons.YesNo);
if (dr == DialogResult.Yes)
{
MessageBox.Show("Login Successfully");
cnn.Close();
this.Hide();
Form2 f2 = new Form2();
f2.ShowDialog();

Answer 1

Hi @Mohamed Rafi N ,
I think your userid and password are unique. So I suggest you could count the same userid and the password. If the count is more than 1, you could login in.

       string strSql = "SELECT COUNT(*) from login where userid=@userid and password=@password";  
      cmd.Connection = cnn;  
      cnn.Open();  
        int count = Convert.ToInt32(command.ExecuteScalar());  
        if (count >= 1)  
            MessageBox.Show("Login Successfully");  
        else  
             MessageBox.Show("Please register");  

Best regards,
Yijing Sun

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Answer 2

You need to use ExecuteReader rather than ExecuteNonQuery.

var results = cmd.ExecuteReader();

Then check results e.g. results.HasRows which returns true if a record was found, false otherwise.