Class DB

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DataBase
{

    public class Person
    {
        public int id;
        public string login;
        public string password;
        public string hint;
    }
    public class Date
    {
        public Date() { Events = new Event[10]; EventsWasRecorded = true; }
        public Date(Event vrem) { Events = new Event[10]; Date.Events[0] = vrem; }
        public static Event[] Events { set; get; }
        public static bool EventsWasRecorded { set; get; }

    }

    public class ClassDataBase
    {
        private static int PrivateKey;
        public ClassDataBase() { }
        public ClassDataBase(int Key)
        {
            PrivateKey = Key;
        }
        public DbConnection OpenConnection()
        {
            var factory = DbProviderFactories.GetFactory("System.Data.SqlClient");
            DbConnection connection = factory.CreateConnection();

            connection.ConnectionString = "data source = boss; initial catalog = manageevent; integrated security = true";

            connection.Open();
            return connection;
        }
        public List<Event> GetEvent()
        {
            List<Event> result = new List<Event>();
            using (var connection = OpenConnection())
            using (var command = connection.CreateCommand())
            {
                command.CommandText = "SELECT * FROM [TabEvent] Where [PrivateKey]=" + PrivateKey + ";";
                var reader = command.ExecuteReader();
                while (reader.Read())
                {
                    var temp = new Event();
                    temp.Id = (int)reader["Id"];
                    temp.NameEvent = (string)reader["Event"];
                    temp.Date = (DateTime)reader["Date"];
                    if (reader["Discription"] != DBNull.Value)
                        temp.Description = (string)reader["Discription"];
                    result.Add(temp);

                }
            }
            return result;
        }

        public Event AddEvent(Event Even)
        {
            using (var connection = OpenConnection())
            using (var command = connection.CreateCommand())
            {
                command.CommandText = "INSERT INTO [TabEvent] ([Date], [Event], [Discription]) OUTPUT INSERTED.[Id] VALUES (@Date, @Event, @Discription)";
                var parameter = command.CreateParameter();
                parameter.ParameterName = "Date";
                parameter.Value = Even.Date;
                command.Parameters.Add(parameter);

                parameter = command.CreateParameter();
                parameter.ParameterName = "Event";
                parameter.Value = Even.NameEvent;
                command.Parameters.Add(parameter);

                parameter = command.CreateParameter();
                parameter.ParameterName = "Discription";
                parameter.Value = Even.Description;
                command.Parameters.Add(parameter);

                Even.Id = (int)command.ExecuteScalar();
                return Even;
            }
        }

        public void EditEvent(Event Even)
        {
            using (var connection = OpenConnection())
            using (var command = connection.CreateCommand())
            {
                command.CommandText = "UPDATE [TabEvent] SET [Date] = @Date, [Event] = @Event, [Discription] = @Discription WHERE [Id] = @Id";

                var parameter = command.CreateParameter();
                parameter.ParameterName = "Date";
                parameter.Value = Even.Date;
                command.Parameters.Add(parameter);

                parameter = command.CreateParameter();
                parameter.ParameterName = "Event";
                parameter.Value = Even.NameEvent;
                command.Parameters.Add(parameter);

                parameter = command.CreateParameter();
                parameter.ParameterName = "Discription";
                parameter.Value = Even.Description;
                command.Parameters.Add(parameter);

                parameter = command.CreateParameter();
                parameter.ParameterName = "Id";
                parameter.Value = Even.Id;
                command.Parameters.Add(parameter);

                command.ExecuteNonQuery();
            }
        }

        public void DeleteEven(Event Even)
        {
            using (var connection = OpenConnection())
            using (var command = connection.CreateCommand())
            {
                command.CommandText = "DELETE FROM [TabEvent] WHERE [Id] = @id";
                var parameter = command.CreateParameter();
                parameter.ParameterName = "id";
                parameter.Value = Even.Id;
                command.Parameters.Add(parameter);
                command.ExecuteNonQuery();
            }
        }
        public void DeleteEven(int id)
        {
            using (var connection = OpenConnection())
            using (var command = connection.CreateCommand())
            {
                command.CommandText = "DELETE FROM [TabEvent] WHERE [Id] = @id";
                var parameter = command.CreateParameter();
                parameter.ParameterName = "id";
                parameter.Value = id;
                command.Parameters.Add(parameter);
                command.ExecuteNonQuery();
            }
        }

    }
    public class Event
    {
        public int Id { get; set; }
        public DateTime Date { get; set; }
        public string NameEvent { get; set; }
        public string Description { get; set; }

        public Event(DateTime Time, string NameEvent, string Description, int id = 0)
        {
            this.Date = Time;
            this.NameEvent = NameEvent;
            this.Description = Description;
            this.Id = id;
        }
        public Event() { }
    }

    public enum TypeQuiry { SETALL, SETLOGIN, SETPASSWORD, ADD, HINT, GETID }
    public class SQLDate
    {
        private SqlConnection Connection()
        {

            string ConnectionString = "data source = boss; initial catalog = manageevent; integrated security = true";
            SqlConnection connection = new SqlConnection(ConnectionString);
            try
            {
                connection.Open();

            }
            catch (SqlException ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }
            return connection;
        }
        public DataSet Get(TypeQuiry quiry, Person person)
        {

            String sqlexpression = transform(quiry, person);
            using (SqlConnection conection = Connection())
            {
                SqlCommand command = new SqlCommand(sqlexpression, conection);
                command = ParametrCommands(quiry, command, person);
                SqlDataAdapter adapter = new SqlDataAdapter(command);

                DataSet dateset = new DataSet();

                adapter.Fill(dateset);

                return dateset;
            }

        }
        private string transform(TypeQuiry quiry, Person person)
        {
            string expression = "";
            switch (quiry)
            {
                case TypeQuiry.SETALL:
                    expression = "GetUsers";
                    break;
                case TypeQuiry.SETLOGIN:
                    expression = "GetLogin";
                    break;
                case TypeQuiry.SETPASSWORD:
                    expression = "GetPas";
                    break;
                case TypeQuiry.ADD:
                    expression = "registration";
                    break;
                case TypeQuiry.HINT:
                    expression = "GetHint";
                    break;
                case TypeQuiry.GETID:
                    expression = "GetId";
                    break;
            }
            return expression;
        }
        public void registration(Person person)
        {

            string expression = transform(TypeQuiry.ADD, person);
            using (SqlConnection conection = Connection())
            {
                SqlCommand command = new SqlCommand(expression, conection);
                command = ParametrCommands(TypeQuiry.ADD, command, person);

            }
        }
        private SqlCommand ParametrCommands(TypeQuiry quiry, SqlCommand command, Person person)
        {
            command.CommandType = CommandType.StoredProcedure;
            switch (quiry)
            {

                case TypeQuiry.ADD:
                    {
                        SqlParameter login = new SqlParameter
                        {
                            ParameterName = "@login",
                            Value = person.login
                        };
                        command.Parameters.Add(login);

                        SqlParameter password = new SqlParameter
                        {
                            ParameterName = "@password",
                            Value = person.password
                        };
                        command.Parameters.Add(password);

                        SqlParameter hint = new SqlParameter
                        {
                            ParameterName = "@hint",
                            Value = person.hint
                        };
                        command.Parameters.Add(hint);

                        command.ExecuteNonQuery();
                    }
                    break;
                default:
                    if ((quiry == TypeQuiry.SETPASSWORD) || (quiry == TypeQuiry.HINT) || (quiry == TypeQuiry.SETLOGIN))
                    {
                        SqlParameter login = new SqlParameter
                        {
                            ParameterName = "@login",
                            Value = person.login
                        };
                        command.Parameters.Add(login);
                    }
                    break;
            }
            return command;
        }

    }

}