trying to remove everything that matches from the database not just firstordefault

user_16003814 0
Viewed 30

this code works but it only removed the first location in the database. I'm fairly new to .Net framework. I understand I'm using FirstOrDefault; I don't know how to search through the database and remove all instances that match the requirements

MMLeagueParticipant removeThisParticipant = db.ParticipatingKids.FirstOrDefault(i=>i.ParticipantId == ParticipantId && i.sport.sport == SportsTab);
if(removeThisParticipant == null)
{
    Console.WriteLine("removeThisParticopant in [IActionResults Remove] was null");
    return RedirectToAction("Dashboard","Dashboard");
}
if(removeThisParticipant != null)
{
    Console.WriteLine("removeThisParticopant in [IActionResults Remove] was NOT null");
    db.ParticipatingKids.Remove(removeThisParticipant);
    db.SaveChanges();
    return RedirectToAction("Dashboard", "Dashboard");
}

What im trying to do:

I want to remove all instances in the database where the conditions are met.

What I tried:

  • .Where() Cannot implicitly convert type 'System.Linq.IQueryable<LeagueProject.Models.MMLeagueParticipant>' to 'LeagueProject.Models.MMLeagueParticipant'.

  • .All(). but this returns a boolean

  • .Contains(). Also returned a boolean

asp.net-mvc database c#
1 Answers

You can use Where instead of FirstOrDefault and Count() to check collection

Example:

IEnumerable<MMLeagueParticipant> removeThisParticipant = db.ParticipatingKids.Where(i=>i.ParticipantId == ParticipantId && i.sport.sport == SportsTab);
if (removeThisParticipant.Count() != 0)
{
     Console.WriteLine("removeThisParticopant in [IActionResults Remove] was NOT null");
     db.ParticipatingKids.RemoveRange(removeThisParticipant);
     db.SaveChanges();
     return RedirectToAction("Dashboard", "Dashboard");   
}
else 
{
    Console.WriteLine("removeThisParticopant in [IActionResults Remove] was null");
    return RedirectToAction("Dashboard","Dashboard");
}
user_52149930
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