Help with linq query. many to many - linq

Question

I have a collection(people) that has a many-to-many reference to another collection(dogs). Suspend your disbelief on how there can be more than one people per dog. People just contains member which is an List<Dog>
I would like to select all the people where the people have a certain property(specified in an IList) and pets have a certain property(specified in an IList).
E.g. I have an IList (used for this query only) with the dog’s property value.
public enum EnumLikesToBite
{
No,
Yes,
Sometimes
}
IList <<EnumLikesToBite>> listDogsMayBite =
{ { EnumLikesToBite.Yes},
{ EnumLikesToBite.Sometimes}};
Then another list for the peoples property:
public enum EnumKeepsPetWith
{
Chain,
String,
Rubberband
}
IList <EnumKeepsPetWith> listPeopleWhoDontRestrainDog =
{ { EnumKeepsPetWith.String },
{ EnumKeepsPetWith.Rubberband}};
How can I query out all the people who have a dog that may bite and don’t restrain dog.
Like this pseudo code:
Var result = from p in People where p.KeepsPet in listPeopleWhoDontRestrainDog and dog.LikesToBite in listDogsMayBite.
Result has all the people. Of course if I could get all the dogs who may bite under those people that would be great.

Answer 1

List<int> mayBite = new List<int>()
{
(int) EnumLikesToBite.Yes,
(int) EnumLikesToBite.Maybe
}
List<int> poorRestraint = new List<int>()
{
(int) EnumKeepsPetWith.String,
(int) EnumKeepsPetWith.RubberBand
}
IQueryable<Person> query =
from p in db.People
where poorRestraint.Contains(p.KeepsPetWith)
where p.DogPeople.Any(dp => mayBite.Contains(dp.Dog.DoesBite))
select p;
var query =
from p in db.People
where poorRestraint.Contains(p.KeepsPetWith)
let bitingDogs =
from dp in p.DogPeople
let d = dp.Dog
where mayBite.Contains(d.DoesBite)
where bitingDogs.Any()
select new {Person = p, BitingDogs = bitingDogs.ToList()};

Answer 2

Maybe this code will help.. One of the possible solution are:
var result =
peoples.Where(y => dontRestrainDog.Contains(y.KeepsPetWith) && y.Dogs.Any(x => dogsMayBite.Contains(x.LikesToBite))).ToList();
result.ForEach(y => y.Dogs = y.Dogs.Where(x => dogsMayBite.Contains(x.LikesToBite)).ToList());
which you can see an example of here:
class Program
{
static void Main(string[] args)
{
IList<EnumLikesToBite> dogsMayBite = new List<EnumLikesToBite>
{
{ EnumLikesToBite.Yes }, { EnumLikesToBite.Sometimes }
};
IList<EnumKeepsPetWith> dontRestrainDog = new List<EnumKeepsPetWith>
{
{ EnumKeepsPetWith.String }, { EnumKeepsPetWith.Rubberband }
};
var peoples = new List<People>();
var dogs = new List<Dog>();
Random gen = new Random(2);
for(int i = 0; i < 10; i++)
{
People p = new People
{
PeopleId = i,
KeepsPetWith = (EnumKeepsPetWith) (gen.Next(10)%3),
Dogs = new List<Dog>()
};
Dog d = new Dog
{
DogId = i,
LikesToBite = (EnumLikesToBite) (gen.Next(10)%3),
Peoples = new List<People>()
};
peoples.Add(p);
dogs.Add(d);
}
for(int i = 0; i < 10; i++)
{
for(int j = 0; j < 10; j++)
{
if (gen.Next(10)>7)
{
peoples[i].Dogs.Add(dogs[j]);
}
if (gen.Next(10)>7)
{
dogs[i].Peoples.Add(peoples[j]);
}
}
}
PrintDogs(dogs);
PrintPeoples(peoples);
var result =
peoples.Where(y => dontRestrainDog.Contains(y.KeepsPetWith) && y.Dogs.Any(x => dogsMayBite.Contains(x.LikesToBite))).ToList();
result.ForEach(y => y.Dogs = y.Dogs.Where(x => dogsMayBite.Contains(x.LikesToBite)).ToList());
Console.WriteLine("===================");
PrintPeoples(result);
Console.ReadLine();
}
private static void PrintPeoples(List<People> peoples)
{
Console.WriteLine("=Peoples=");
foreach (var people in peoples)
{
Console.WriteLine("Id: {0}", people.PeopleId);
Console.WriteLine("KeepsPetWith: {0}", people.KeepsPetWith);
Console.WriteLine("Dogs: ");
foreach (var dog in people.Dogs)
{
Console.Write("{0}, ", dog.DogId);
}
Console.WriteLine();
}
}
private static void PrintDogs(List<Dog> dogs)
{
Console.WriteLine("=Dogs=");
foreach (var dog in dogs)
{
Console.WriteLine("Id: {0}", dog.DogId);
Console.WriteLine("LikesToBite: {0}", dog.LikesToBite);
Console.WriteLine("Peoples: ");
foreach (var people in dog.Peoples)
{
Console.Write("{0}, ", people.PeopleId);
}
Console.WriteLine();
}
}
}
public class People
{
public int PeopleId { get; set; }
public EnumKeepsPetWith KeepsPetWith { get; set; }
public IList<Dog> Dogs { get; set; }
}
public class Dog
{
public int DogId { get; set; }
public EnumLikesToBite LikesToBite { get; set; }
public IList<People> Peoples { get; set; }
}
public enum EnumLikesToBite
{
No,
Yes,
Sometimes
}
public enum EnumKeepsPetWith
{
Chain,
String,
Rubberband
}