Learning/Mysql-example/Database/DBConnectGeneral.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Globalization;
using System.Linq;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml.Linq;
using Google.Protobuf.WellKnownTypes;
using MySql.Data.MySqlClient;
using Mysql_example.Database.Schema;
using MySqlX.XDevAPI.Common;
using MySqlX.XDevAPI.Relational;
using static System.ComponentModel.Design.ObjectSelectorEditor;
using static System.Runtime.InteropServices.JavaScript.JSType;
using static Mysql_example.Database.DBConnectGeneral;

namespace Mysql_example.Database
{
    class DBConnectGeneral
    {
        public MySqlConnection connection;
        private string server;
        private string database;
        private string uid;
        private string password;

        public DBConnectGeneral()
        {
            this.server = Config.DBHost;
            this.database= Config.DBName;
            this.uid= Config.DBUser;
            this.password = Config.DBPass;
            Initialize();
        }

        //Connection Handeling
        private void Initialize()
        {
            string connectionPayload = $"SERVER={server};DATABASE={database};UID={uid};PASSWORD={password};";
            connection = new MySqlConnection(connectionPayload);
        }
        public bool OpenConnection()
        {
            try
            {
                connection.Open();
                return true;
            } catch (MySqlException exception)
            {
                switch (exception.Number)
                {
                    case 0:
                        MessageBox.Show("Cannot connect to server.  Contact administrator");
                        break;
                    case 1045:
                        MessageBox.Show("Invalid username/password, please try again");
                        break;
                    default:
                        MessageBox.Show($"Error: {exception.Message}");
                        break;
                }
                return false;
            }
        }
        public bool CloseConnection()
        {
            try
            {
                connection.Close();
                return true;
            } catch (MySqlException exception)
            {
                MessageBox.Show(exception.Message);
                return false;

            }
        }

        // Getting Information
        public List<string> [] Select(string table, List<string> fields)
        {
            string querry = "SELECT ";
            foreach (string field in fields)
            {
                querry += $"`{field}`, ";
            }
            querry = querry.Substring(0, querry.Length - 2);
            querry += $" FROM `{table}`";

            List<string>[] response = new List<string>[fields.Count];
            for (int i = 0; i < fields.Count; i++)
            {
                response[i] = new List<string>();
            }

            if(this.OpenConnection())
            {
                MySqlCommand selectCmd = new MySqlCommand(querry, connection);
                MySqlDataReader dataReader= selectCmd.ExecuteReader();

                while (dataReader.Read())
                {
                    for (int i = 0; i < fields.Count; i++)
                    {
                        response[i].Add(dataReader[fields[i]] + "");
                    }
                }
                dataReader.Close();
                CloseConnection();
            }
            return response;
        }
        public List<string>[] Select(string table, List<string> fields, string selector)
        {
            string querry = "SELECT ";
            foreach (string field in fields)
            {
                querry += $"`{field}`, ";
            }
            querry = querry.Substring(0, querry.Length - 2);
            querry += $" FROM `{table}` WHERE {selector}";

            List<string>[] response = new List<string>[fields.Count];
            for (int i = 0; i < fields.Count; i++)
            {
                response[i] = new List<string>();
            }

            if (this.OpenConnection())
            {
                MySqlCommand selectCmd = new MySqlCommand(querry, connection);
                MySqlDataReader dataReader = selectCmd.ExecuteReader();

                while (dataReader.Read())
                {
                    for (int i = 0; i < fields.Count; i++)
                    {
                        response[i].Add(dataReader[fields[i]] + "");
                    }
                }
                dataReader.Close();
                CloseConnection();
            }
            return response;
        }
        
        // Modifying Information
        public int Update(string table, List<string> fields, List<object> values, string selector)
        {

            string querry = $"UPDATE `{table}` SET ";
            if (fields.Count != values.Count) throw new Exception("Count of Fields and Values to Update doesnt match");

            for(int i = 0; i < fields.Count;i++)
            {
                string value = values[i] != null ? "'" + values[i].ToString() + "'" : "NULL";
                querry += $"`{fields[i]}`= {value},";
            }
            querry = querry.Remove(querry.Length -1);
            querry += $" WHERE {selector};";

            if (this.OpenConnection())
            {
                MySqlCommand updateCommand = new MySqlCommand();
                updateCommand.CommandText = querry;
                updateCommand.Connection = connection;
                try
                {
                    int affected = updateCommand.ExecuteNonQuery();
                    return affected;
                }
                catch(Exception ex)
                {
                    MessageBox.Show(ex.Message, "There Was an Error Trying to Update.");
                } finally
                {
                    CloseConnection();
                }
            }
            return 0;
        }

        public UInt64 Insert(string table, List<string> fields, List<object> values)
        {
            if (fields.Count != values.Count) throw new Exception("Count of Fields and Values to Update doesnt match");

            string querry = $"INSERT INTO `{table}` (";
            for (int i = 0; i < fields.Count; i++)
            {
                querry += $"`{fields[i]}`,";
            }
            querry = querry.Remove(querry.Length - 1);
            querry += $") VALUES (";
            for (int i = 0; i < values.Count; i++)
            {
                string value = values[i] != null ? "'" + values[i].ToString() + "'" : "NULL";
                querry += $"{value},";
            }
            querry = querry.Remove(querry.Length - 1);
            querry += ");";

            if (this.OpenConnection())
            {
                MySqlCommand insertCommand = new MySqlCommand();
                insertCommand.CommandText = querry;
                insertCommand.Connection = connection;
                try
                {
                    insertCommand.ExecuteNonQuery();
                    return insertCommand.LastInsertedId < 0 ? 0 : (UInt64)insertCommand.LastInsertedId;
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "There Was an Error Trying to Insert.");
                }
                finally
                {
                    CloseConnection();
                }
            }
            return 0;
        }
        public void Delete(string table, string selector)
        {
            string querry = $"DELETE FROM `{table}` WHERE {selector};";
            if (this.OpenConnection())
            {
                MySqlCommand deleteCommand = new MySqlCommand();
                deleteCommand.CommandText = querry;
                deleteCommand.Connection = connection;
                deleteCommand.ExecuteNonQuery();
                CloseConnection();
            }
        }
    }
}