用户名和密码不区分大小写

Question

我知道我没有将我的密码存储在哈希中，但是出于这个数据库的目的，这无关紧要。

该代码引用了一个SQL数据库，该数据库将密码存储为纯文本

这是代码：

/*Checks to see if the username and password matcch the database
         If it does, it lets you in, if not you displays an error message*/
        string user = textBox1.Text.ToString();
        string pass = textBox2.Text;
        MySqlConnection conn = new MySqlConnection(ConnectionString);
        MySqlDataAdapter sda = new MySqlDataAdapter("SELECT COUNT(*) from Employees WHERE UserName = '"+(user)+ "' and Password = '"+(pass)+"' collate Latin1_Genral_CS_AS", conn);
        DataTable dt = new DataTable();
        sda.Fill(dt);
        if(dt.Rows[0][0].ToString() == "1")
        {
            HomeScreen home = new HomeScreen();
            this.Hide();
            home.ShowDialog();
        }
        else
        {
            MessageBox.Show("Incorrect Username or Password", "alter", MessageBoxButtons.OK, MessageBoxIcon.Error );
        }            

Answer 1

您可以将输入值和表格列都转换为lowercase或uppercase：

/*Checks to see if the username and password matcch the database
         If it does, it lets you in, if not you displays an error message*/
        string user = textBox1.Text.ToLower();
        string pass = textBox2.Text.ToLower();
        MySqlConnection conn = new MySqlConnection(ConnectionString);
        MySqlDataAdapter sda = new MySqlDataAdapter("SELECT COUNT(*) from Employees WHERE LOWER(UserName) = '"+(user)+ "' and LOWER(Password) = '"+(pass)+"' collate Latin1_Genral_CS_AS", conn);
        DataTable dt = new DataTable();
        sda.Fill(dt);
        if(dt.Rows[0][0].ToString() == "1")
        {
            HomeScreen home = new HomeScreen();
            this.Hide();
            home.ShowDialog();
        }
        else
        {
            MessageBox.Show("Incorrect Username or Password", "alter", MessageBoxButtons.OK, MessageBoxIcon.Error );
        }   

Answer 2

你可以alter你的database使用你想要的collation：

ALTER DATABASE DBNAME CHARACTER SET utf8 COLLATE utf8_general_ci;

但是，这仅适用于新表。你可以alter a table column使用你喜欢的collation：

ALTER TABLE table_name MODIFY column_name column_datatype COLLATE utf8_bin;