Question 120956 in Mysql Question posted in
The official MySQL documentation can be found here.

How to have MySQL check and verify a static result from another column

Here is my current running code:

 private void button1_Click(object sender, EventArgs e)
    {
        string server = "207.244.70.217";
        string database = "nextgene_NGH";
        string uid = "EXAMPLEUID";
        string password = "EXAMPLEPASSWORD";
        string ssl = "None";

        string connectionString = $"SERVER={server};DATABASE={database};UID={uid};PASSWORD={password};SSL Mode={ssl};";    
        using var connection = new MySqlConnection(connectionString);
        connection.Open();
        using var command = new MySqlCommand("SELECT members_pass_hash FROM core_members && WHERE name = @name;", connection);
        command.Parameters.AddWithValue("@name", maskedTextBox1.Text);
        var hashedPassword = (string) command.ExecuteScalar();
        if (!(hashedPassword is null && !BCrypt.Net.BCrypt.Verify(maskedTextBox2.Text, hashedPassword)))
        {
            
            MessageBox.Show("Login Successful");
        }
    }

The above code works to login my database. The problem is it only checks to see the login name and the password. As these two work, i can’t figure out how to call another column mgroup_others and check to see if there is a result of 7 there or not. I have attached a photo of my database here:

mgroup_others

Here is my rewritten function:

   private void button1_Click(object sender, EventArgs e)
    {
        string server = "207.244.70.217";
        string database = "nextgene_NGH";
        string uid = "EXAMPLEUID";
        string password = "EXAMPLEPASSWORD";
        string ssl = "None";
        string vipcheck = "7";

        string connectionString = $"SERVER={server};DATABASE={database};UID={uid};PASSWORD={password};SSL Mode={ssl};";    
        using var connection = new MySqlConnection(connectionString);
        connection.Open();
        using var command = new MySqlCommand("SELECT members_pass_hash AND mgroup_others FROM core_members && WHERE name = @name;", connection);
        command.Parameters.AddWithValue("@name", maskedTextBox1.Text);
        var hashedPassword = (string) command.ExecuteScalar();
        if (!(hashedPassword is null && !BCrypt.Net.BCrypt.Verify(maskedTextBox2.Text && vipcheck != mgroup_others, hashedPassword)))
        {
            
            MessageBox.Show("Login Successful");
        }
    }
Tags:

3

Answers


  1. 0

    The SELECT clause should look like this:

    SELECT members_pass_hash, mgroup_others

    Then, since you are getting more than one value, you should use either ExecuteReader() or using a DataAdapter to Fill() a DataTable, so you can use all the value. If you want to have success as a developer, this is code you should write yourself, so you understand it, rather than just copying what we give you.

    Login or Signup to reply.
  2. 0

    It appears the mentioned SQL query is wrong, so change your SELECT query as follows:

    SELECT members_pass_hash, mgroup_others FROM core_members WHERE name = @name;

    Refer to this doc to understand how to write proper MySql queries.

    Login or Signup to reply.
  3. 0

    If all you need to know is if the value in the mgroup_others column is equal to 7, you can update your SQL as follows:

    using var command = new MySqlCommand("""
    SELECT members_pass_hash
    FROM core_members
    WHERE name = @name AND mgroup_others = 7;
    """, connection);
command.Parameters.AddWithValue("@name", maskedTextBox1.Text);
var hashedPassword = (string) command.ExecuteScalar();

    The advantage of this approach (compared to some other answers) is that you can still use ExecuteScalar because you’re only reading a single value.

    If you need to retrieve the value of mgroup_others and examine it in your C# code, you should use one of the other answers that shows how to use ExecuteReader or a DataAdapter.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search