avtoservis/Servise/Classes/DataBase.cs

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

namespace Servise
{
    internal class DataBase
    {
        /// <summary>
        /// установка соединения, указывается название сервера и входные данные
        /// </summary>
        SqlConnection sqlConnection = new SqlConnection(@"Data Source=ngknn.ru;Initial Catalog=YPpract;Persist Security Info=True;User ID=31П;Password=12357"); 

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

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

        public SqlConnection getConect()
        {
            return sqlConnection;
        }

    }
}