问LINQ to NHibernate和字符串比较的奇怪问题

EN

    internal List<DamageList> SearchDamageList(
    DateTime? sendDateFromSearch, DateTime? sendDateToSearch, string damageNumberSearch,
    string insuranceContractSearch)
    {
        var q = from dl in session.Linq<DamageList>()
                where
                CommonHelper.IsDateBetween(dl.SendDate, sendDateFromSearch, sendDateToSearch) &&
                //MyCompareFunc(dl.DamageNumber, damageNumberSearch) &&
                dl.DamageNumber.Contains(damageNumberSearch) &&
                insuranceContractSearch == null ? true : CommonHelper.IsSame(dl.InsuranceContract, insuranceContractSearch)
                select dl;

        return q.ToList<DamageList>();
    }

    private bool MyCompareFunc(string damageNumber, string damageNumberSearch)
    {
        return damageNumber.Contains(damageNumberSearch);
    }