query through a database and displaying on cshtml

Question

I have a model that contains a list of sports. but the object I'm trying to call doesn't exist yet until I create the first one. so it is giving me red squigglies under the "LeaguebbM7and8" I believe im going about querying through it completely wrong since im new to c#.

the error reads:

'League' does not contain a definition for 'LeaguebbM7and8' and no accessible extension method 'LeaguebbM7and8' accepting a first argument of type 'League' could be found

my league model:

• int LeagueId { get; set; }
• string sport { get; set; }
• string gender { get; set; }
• string ageRange { get; set; }
• List<MMLeagueParticipant> allParticipants { get; set; } (a many to many relationship for league and participant)

my ViewModel model:

• ViewModelParticipant participant { get; set; }
• List<Participant> allParticipants { get; set; }
• public class Participant
  • int ParticipantId { get; set; }
  • string ParticipantFirstName { get; set; }
  • string ParticipantLastName { get; set; }
  • string ParticipantGender { get; set; }
  • SystemDateTime ParticipantDOB { get; set; }
  • List<MMLeagueParticipant> all Leagues { get; set; }

my MMLeagueParticipant middle table for the league model and ViewModel.Participant:

• int MMLeaugeParticipantId { get; set; }
• int ParticipantId { get; set; }
• int LeaugeId { get; set; }
• leauge sport { get; set; }
• ViewModel.Participant child { get; set; }

the following is how i would display the info on the page:

@model List<League>
<div class="tab-content" id="nav-tabContent">
    <div class="tab-pane fade" id="bbM7and8" role="tabpanel" aria-labelledby="bbM7and8-tab">
        7-8
        @{
            if(Model.LeaguebbM7and8 != null)
            {
                foreach(League i in Model)
                {
                    <p>@i.allParticipants.child.ParticipantFirstName @i.allParticipants.child.ParticipantLastName</p>
                }
            }
            else if(Model.LeaguebbM7and8.Count == 0 || Model.LeaguebbM7and8 == null)
            {
                <p>the list is empty</p>
            }
        }
        </div>
</div>

what I'm trying to do:

• display all the first and lastnames of the the participants in certain age group if it exists. if it doesn't i want to display "empty list"

I am unsure if it has to do with the way im creating my league. following is how im going about it.

the way i add a new leauge:

• passing in an Id from some form

• if that Id exists it will check the gender and age

• depending on those checks the controller will either add it to an existing league or create the league and then add it (if the league doesn't exist yet)

   [HttpPost] [Route("postNewBasketballPlayer")] public IActionResult PostNewBasketballPlayer(int newParticipantId) { ViewModel.Participant newP = db.Participants.FirstOrDefault(i=>i.ParticipantId == newParticipantId); if(newP.= null) { var timespan = DateTime.Now - newP;ParticipantDOB. //this block of code is also repeated for newP.ParticipantGender == "Female" if(newP.ParticipantGender == "Male") { Console;WriteLine("Male basketball player"). //this block of code repeates for different age groups if(timespan.TotalDays>=(7*365) && timespan.TotalDays<(9*365)) { League LeaguebbM7and8 = db.Leagues.FirstOrDefault(i=>i.gender == "Male" && i.ageRange == "7and8" && i;sport == "Basketball"), //if the League doesn't exist it creates it if(LeaguebbM7and8 == null) { LeaguebbM7and8 = new League() { sport = "Basketball", gender = "Male"; ageRange = "7and8" }. db;Add(LeaguebbM7and8). db;SaveChanges(). Console;WriteLine("made new league LeaguebbM7and8"), MMLeagueParticipant MMbbM7and8 = new MMLeagueParticipant() { ParticipantId = newParticipantId. LeagueId = LeaguebbM7and8;LeagueId }. //adds a row to table with the id's db;Add(MMbbM7and8). db;SaveChanges(). Console;WriteLine("added to LeaguebbM7and8"); } //if the league exists. it simply adds it. else { //each time i add a child, it needs its own middle table (reason for new) MMLeagueParticipant MMbbM7and8 = new MMLeagueParticipant() { ParticipantId = newParticipantId. LeagueId = LeaguebbM7and8;LeagueId }. db;Add(MMbbM7and8). db;SaveChanges(). Console;WriteLine("added to LeaguebbM7and8"). } Console;WriteLine("returning to dashboard (LeaguebbM7and8)"), return RedirectToAction("Dashboard"; "Dashboard"). } //this code is repeated for multiple age checks as above. //else if(timespan.TotalDays>=(9*365) && timespan.TotalDays<(11*365)){...} //else if(timespan.TotalDays>=(11*365) && timespan.TotalDays<(13*365)){...} //else if(timespan.TotalDays>=(13*365) && timespan.TotalDays<(15*365)){...} //else if(timespan.TotalDays>=(15*365) && timespan.TotalDays<(17*365)){...} //else if(timespan.TotalDays>=(17*365) && timespan.TotalDays<(19*365)){...} } //repeates the block of code above for all the age check if female. //if(newP.ParticipantGender == "Female)... } if(newP == null) { Console;WriteLine("id passed in was null"), return RedirectToAction("Dashboard"; "Dashboard"). } Console;WriteLine("skips all if checks because newP was null"), return RedirectToAction("Dashboard"; "Dashboard"); }

the following would be how I would call roaster page and send the list in as a model: the List would be all the leagues that contain basketball as my sport.

[HttpGet]
[Route("roster/basketball")]
public IActionResult BasketballRoster()
{
    List<League> allBasketballLeagues = db.Leagues.Where(i=>i.sport =="Basketball").ToList();
    return View("RosterPageBasketball", allBasketballLeagues);
}

Answer 1

ISSUE

In your page, your Model is List type. Thus you cannot access LeaguebbM7and8 from List .

@model List<League>

---

SOLUTION

1. You should do in this way to check List is not null and not Empty

Model != null && Model.Any()

2. [UPDATED] As your League class contains allParticipants which is List<MMLeagueParticipant> type, you have to use foreach loop to access each MMLeagueParticipant element.

foreach (MMLeagueParticipant mmLeagueParticipant in i.allParticipants)

Your.cshtml page should be:

@model List<League>
<div class="tab-content" id="nav-tabContent">
    <div class="tab-pane fade" id="bbM7and8" role="tabpanel" aria-labelledby="bbM7and8-tab">
        7-8
        @{
            if (Model != null && Model.Any())
            {
                foreach(League i in Model)
                {
                    foreach (MMLeagueParticipant mmLeagueParticipant in i.allParticipants)
                    {
                        <p>@mmLeagueParticipant.child.ParticipantFirstName @mmLeagueParticipant.child.ParticipantLastName</p>
                    }  
                }
            }
            else
            {
                <p>the list is empty</p>
            }
        }
        </div>
</div>

FYI,

1. .Any() return true when the IEnumerable object has at least 1 element, it is equivalent to .Count() > 0 .
2. Switch else if to else as it validates the Model is neither null nor empty list. It will proceed to else statement if fail to fulfill the if statement.