public void EnrollStudent(EnrollStudentRequest request)
        {
            using (var client = new SqlConnection("Data Source=db-mssql;Initial Catalog=s19036;Integrated Security=True"))
            using (var com = new SqlCommand())
            {
                var studies = request.Studies;
                com.Connection = client;
                client.Open();
                var tran = client.BeginTransaction();

                try
                {
                    com.CommandText = "SELECT * FROM studies WHERE name = @studiesName";
                    com.Parameters.AddWithValue("studiesName", studies.name);
                    var db = com.ExecuteReader();
                    if (!db.Read())
                    {
                        tran.Rollback();
                        return;
                        //---Blad 400
                    }

                    // int id = (int) db["IdStudy"];
                    // Console.WriteLine(id);
                    // com.CommandText = "Select MAX(StartDate) FROM Enrollment WHERE Semenster = 1 && IdStudy = @study";
                    // com.Parameters.AddWithValue("study", id);

                    // db = com.ExecuteReader();
                    // if (db.Read())
                    // {
                    //     Console.WriteLine(db["IdEntrollemnt"]);
                    // }
                    // else
                    // {
                    //     Console.WriteLine("Dziala");
                    // }

                    com.ExecuteNonQuery();
                    tran.Commit();

                }
                catch (SqlException e)
                {
                    tran.Rollback();
                }

            }
}