CategoryRepository.cs

using System;
using System.Collections.Generic;
using System.Linq;
using EduitorNetCore.Models.Database;
using EduitorNetCore.Models.VOs.Reduceds;
using EduitorNetCore.Repositories.Database;
using EduitorNetCore.Repositories.Interfaces;
using Microsoft.EntityFrameworkCore;

namespace EduitorNetCore.Repositories
{
    public class CategoryRepository : Repository<Category>, ICategoryRepository
    {
        public CategoryRepository(DataBaseContext context) : base(context) { }

        public IEnumerable<Category> GetAllIncludeInCategoriesId(IEnumerable<int> categoryIds)
        {
            return Context.Categories.Where(c => categoryIds.Contains(c.Id));
        }
      
        // we need to use this GetAll method
        public IEnumerable<Category> GetAllWithRelatedEntities() => Context.Categories.Include(c => c.Resources);
    }
}

MetricApiController.cs

private List<SkillsByCategoryVO> GetSkillsByCategoryAndRole(User currentUser, string startingDate, int? schoolId, string role)
{
    return UnitOfWork.CategoryRepository.GetAllWithRelatedEntities()
            .Select(c => new SkillsByCategoryVO(new CategoryVO(c),
            c.Resources.Where(r => r.ResourceAccesses.Where(ra =>
                                   ra.UpdatedAt >= DateTime.ParseExact(startingDate, "dd/MM/yyyy", CultureInfo.InvariantCulture)
                                   && (VerifyConditionByRole(role, schoolId, ra))).Any())
                .SelectMany(r => r.SkillResources
                .GroupBy(sr => sr.SkillId)
                .Select(srgroup => new SkillPercentageVO(
                 new SkillVO(srgroup.Select(sr => sr.Skill).FirstOrDefault()),
                 100 * ((float)srgroup.Count() / r.SkillResources.Count)))).ToList())).ToList();
}

private bool VerifyConditionByRole(string role, int? schoolId, ResourceAccess ra)
{
    if (role == "Admin")
        return (schoolId == null || ra.User.SchoolGroup.Schools.Where(s => s.Id == schoolId).Any());
    else if (role == "Teacher")
        return ra.User.TeacherSchools.Where(ts => ts.SchoolId == schoolId).Any();
    else if (role == "Manager")
        return ra.User.ManagerSchools.Where(ts => ts.SchoolId == schoolId).Any();
    throw new ArgumentException();
}