Linq

            var model = await db.Users.Where(u => u.Id == id).Select(p => new ProfilePictureServiceModel
            {
                Id = p.Pictures
           .Where(pp => pp.isProfilePicture == true)
           .Select(i => i.PictureId).FirstOrDefault(),

                PictureByteArray = p.Pictures
           .Where(pp => pp.isProfilePicture == true)
           .Select(cpp => cpp.PictureByteArray)
           .FirstOrDefault(),

                allPage = (p.Pictures.Count() - 1) % ServicesDataConstraints.EditProfilePictureServicePageSize == 0 ? ((p.Pictures.Count() - 1) / ServicesDataConstraints.EditProfilePictureServicePageSize) : (((p.Pictures.Count() - 1) / ServicesDataConstraints.EditProfilePictureServicePageSize) + 1),

                Pictures = p.Pictures
           .Where(f => f.isProfilePicture == false)
           .OrderByDescending(o => o.PictureId)
           .Skip((page - 1) * ServicesDataConstraints.EditProfilePictureServicePageSize)
           .Take(ServicesDataConstraints.EditProfilePictureServicePageSize)
           .Select(k =>
           new ChildPicturesServiceModel
           {
               PictureByteArray = k.PictureByteArray,
               Id = k.PictureId,

           })
           .ToList()
            }).FirstOrDefaultAsync();