Gostinitsa/Database.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace Khozeev8
{
    class Database
    {
        SqlConnection sqlConnection = new SqlConnection("Data Source=CLASS31000;Initial Catalog=KhozeeevPC_12;Integrated Security=True");

        public void openConnection()
        {
            if (sqlConnection.State == System.Data.ConnectionState.Closed)
            {
                sqlConnection.Open();
            }
        }

        public void closeConnection()
        {
            if (sqlConnection.State == System.Data.ConnectionState.Open)
            {
                sqlConnection.Close();
            }
        }

        public SqlConnection GetConnection()
        {
            return sqlConnection;
        }
    }
}