Convert int and biging for filter ListViewModel C#

Question

I created a ListViewModel something like this

public class ListPersonalsViewModel
{
    public long PersonalID { get; set; }
    public int NationalCode { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

and I use this code

public List<ListPersonalsViewModel> GetNamePersonal(string filter = "")
{
    if (filter == null)
    {
        return db.tblPersonals.Select(p => new ListPersonalsViewModel()
                    {
                        NationalCode = p.NationalCode,
                        PersonalID = p.PersonalID,
                        FirstName = p.FirstName,
                        LastName = p.LastName
                    }).ToList();
    }

    return db.tblPersonals.Where(p => p.FirstName.Contains(filter)||
                                      p.LastName.Contains(filter) ||
                                      p.NationalCode.Contains(filter) ||
                                      p.PersonalID.Contains(filter))
                          .Select(p => new ListPersonalsViewModel()
                                           {
                                               NationalCode = p.NationalCode,
                                               PersonalID = p.PersonalID,
                                               FirstName = p.FirstName,
                                               LastName = p.LastName
                                           }).ToList();
}

Now my question: how i can convert PersonalID and NationalCode to string for work here?

Here just 2 my string filter work

i receive this 2 error

Error CS1929 'long' does not contain a definition for 'Contains' and the best extension method overload 'Queryable.

Error CS1929 'int' does not contain a definition for 'Contains' and the best extension method overload 'Queryable.

i think this is better for understanding

Answer 1

with this code my problem solved

,,,

return db.tblPersonals.Where(p => p.FirstName.Contains(filter)||
                                  p.LastName.Contains(filter) ||
                                  p.NationalCode.ToString().Contains(filter) ||
                                  p.PersonalID.ToString().Contains(filter))
                      .Select(p => new ListPersonalsViewModel()

,,,