public IActionResult Index(string nameQuery = "", string surnameQuery = "", string patronymicNameQuery = "")
{
Func <Athlete, bool> predicate = (Athlete athlete) =>
((nameQuery is null) || athlete.Name.Contains(nameQuery)) &&
((surnameQuery is null) || athlete.Surname.Contains(surnameQuery)) &&
((patronymicNameQuery is null) || athlete.PatronymicName.Contains(patronymicNameQuery));
List <Athlete> allAthletes = _athleteRepository.Get(predicate);
List <Sport> allSports = _sportRepository.GetAll();
List <AthleteDto> result = (from athlete in allAthletes
join sport in allSports on athlete.SportId equals sport.Id
select new AthleteDto
{
Id = athlete.Id,
Name = athlete.Name,
Surname = athlete.Surname,
PatronymicName = athlete.PatronymicName,
SportName = sport.Name
}).ToList();
return(View(result));
}