Question

I have a list of objects (Locations). Every location can have multiple categories. I have a list of integers (CategoryId’s). Based on that I need to filter locations:

List<int> categoriesToLoad = new List<int>();
// fill list
var allLocations = locationRepository.GetLocations().Where(...
var filteredLocations = from m in model
                             where categoriesToLoad.Contains(m.LocationCategories.FirstOrDefault() == null ? -1 : m.LocationCategories.FirstOrDefault().PlaceCategoryId)
                             select m;

This works only for one category, I don’t know how to fix code to compare all categories that are attached to location.

Answer 1

You want Any.

var filteredLocations = 
       model.Where(m => m.LocationsCategories
            .Any(c => categoriesToLoad.Contains(c.PlaceCategoryId)));