Question 235584 in Mysql Question posted in
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C# MySQL Object cannot be cast from DBNull to other types

I can’t connect to my MySQL server with my CLI!

Im trying to connect to my mysql database using c# but i get Object cannot be cast from DBNull to other types. for no reason!

using MythicalDash;
using MySql.Data.MySqlClient;

namespace MythicalDash
{
    public class Database {
        FileManager fm = new FileManager();
        
        public void Configurator() {
            Program.logger.Log(LogType.Info, "Hi, please fill in your database configuration for MythicalDash.");
            Console.Write("Host: ");
            #pragma warning disable
            string host = Console.ReadLine();
            Console.Write("Port: ");
            string port = Console.ReadLine();
            Console.Write("Username: ");
            string username = Console.ReadLine();
            Console.Write("Password: ");
            string password = Console.ReadLine();
            Console.Write("Database Name: ");
            string dbName = Console.ReadLine();
            #pragma warning restore
            string connectionString = "Server="+host+";Port="+port+";Database="+dbName+";Uid="+username+";Pwd="+password+";";
            try
            {
                var conn = new MySqlConnection(connectionString);
                conn.Open();
                Program.logger.Log(LogType.Info,"Done");
                Environment.Exit(0x0);
            }
            catch (Exception ex)
            {
                Program.logger.Log(LogType.Error,$"Failed to connect to MySQL: {ex.Message}");
                Environment.Exit(0x0);
            }
        }
    }
}
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2

Answers


  1. Chosen as BEST ANSWER
    0

    I finally managed to get it to work here is my code:

    using MythicalDash;
using MySqlConnector;
namespace MythicalDash
{
    public class Database
    {
        FileManager fm = new FileManager();
        public void Configurator()
        {
            #pragma warning disable
            Program.logger.Log(LogType.Info, "Hi, please fill in your database configuration for MythicalDash.");
            Console.Write("Host: ");
            string host = Console.ReadLine();
            Console.Write("Port: ");
            string port = Console.ReadLine();
            Console.Write("Username: ");
            string username = Console.ReadLine();
            Console.Write("Password: ");
            string password = Console.ReadLine();
            Console.Write("Database Name: ");
            string dbName = Console.ReadLine();
            #pragma warning restore
            // Validate input
            if (string.IsNullOrEmpty(host) || string.IsNullOrEmpty(port) || string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password) || string.IsNullOrEmpty(dbName))
            {
                Program.logger.Log(LogType.Error, "Invalid input. Please provide all the required values.");
                Environment.Exit(0x0);
            }
            try
            {
                using var connection = new MySqlConnection($"Server={host};Port={port};User ID={username};Password={password};Database={dbName}");
                connection.Open();
                Program.logger.Log(LogType.Info, "Connected to MySQL, saving database configuration to config.");
                connection.Close();
                
            }
            catch (Exception ex)
            {
                Program.logger.Log(LogType.Error, $"Failed to connect to MySQL: {ex.Message}");
                Environment.Exit(0x0);
            }
        }
    }
}

  2. 0

    try to use this code:

    public void Configurator() {
    Program.logger.Log(LogType.Info, "Hi, please fill in your database configuration for MythicalDash.");
    Console.Write("Host: ");
    string host = Console.ReadLine();
    Console.Write("Port: ");
    string port = Console.ReadLine();
    Console.Write("Username: ");
    string username = Console.ReadLine();
    Console.Write("Password: ");
    string password = Console.ReadLine();
    Console.Write("Database Name: ");
    string dbName = Console.ReadLine();
    
    // Validate input
    if (string.IsNullOrEmpty(host) || string.IsNullOrEmpty(port) || string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password) || string.IsNullOrEmpty(dbName)) {
        Program.logger.Log(LogType.Error, "Invalid input. Please provide all the required values.");
        Environment.Exit(0x1);
    }

    string connectionString = "Server=" + host + ";Port=" + port + ";Database=" + dbName + ";Uid=" + username + ";Pwd=" + password + ";";
    try
    {
        var conn = new MySqlConnection(connectionString);
        conn.Open();
        Program.logger.Log(LogType.Info, "Connected to MySQL successfully.");
        Environment.Exit(0x0);
    }
    catch (Exception ex)
    {
        Program.logger.Log(LogType.Error, $"Failed to connect to MySQL: {ex.Message}");
        Environment.Exit(0x1);
    }
}

    With this, you can sure that the mandatories data are provided.

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