使用Linq构建复杂的存储库没有正确过滤结果？

Question

我有一个通用的存储库表单，我使用Autofac将依赖注入WebApi 2.0控制器。我正在构建一个GET方法，该方法接受一些可选参数，以便从安装程序的角度进行一站式过滤结果。

控制器的DI是;

public class InstallerService : EntityService<Installer>, IInstallerService
{
    IContext _context;

public InstallerService(IContext context)
    : base(context)
{
    _context = context;
    _dbset = _context.Set<Installer>();
}

我需要帮助的WebApi控制器GET方法如下;

public IHttpActionResult GetAppointments(
            int id,
            string policynumber = null,
            bool includearchived = false, 
            int? pagesize = null, 
            int? pageoffset = null)
        {
        var predicate = PredicateBuilder.True<Installer>();

        predicate = predicate.And(x => x.ID == id);

        if (policynumber != null)
            predicate = predicate.And(x => x.Appointments.Any(y => y.Vehicle.InsurancePolicyVehicles.Any(z => z.Policy.PolicyNumber.Contains(policynumber))));

        if (!includearchived)
            predicate = predicate.And(x => x.Archived == false);

        var results = _Service.GetAppointments(predicate, pageoffset, pagesize);

        var filtered = from x in results
                       select new
        {
                           appointments = x.Appointments.Select(y => new
                           {
                               appointmentid = y.ID,
                               driverid = y.Driver.ID,
                               policyid = y.Vehicle.InsurancePolicyVehicles.Select(z => z.Policy.ID),
                               policynumber = y.Vehicle.InsurancePolicyVehicles.Select(z => z.Policy.PolicyNumber),
                               created = y.CreatedDate,
                               policyholder = y.Driver.PolicyHolder,
                               date = y.Date,
                               ampm = y.AmPm,
                               installer = new
                               {
                                   installerid = x.ID,
                                   name = x.Name,
                                   contact = x.Contact,
                                   qascore = x.QAScore,
                                   address1 = x.Address1,
                                   address2 = x.Address2,
                                   address3 = x.Address3,
                                   address4 = x.Address4,
                                   city = x.City,
                                   county = x.County,
                                   postcode = x.PostCode,
                                   country = x.Country,
                                   email = x.Email,
                                   web = x.Web,
                                   archived = x.Archived,
                                   numberofinstalls = x.NumberOfInstalls,
                                   numberoffailedinstalls = x.NumberOfFailedInstalls
                               },
                               device = new
                               {
                                   deviceid = y.Device.ID,
                                   iccid = y.Device.ICCID,
                                   imei = y.Device.IMEI,
                                   msisdn = y.Device.MSISDN,
                               },
                               status = y.Status,
                               archived = y.Archived
                           })
        };

        var json = JsonConvert.SerializeObject(filtered);
        if (json != "[]") 
            json = json.Replace("[{\"appointments\":", "").TrimEnd('}',']');

        return Ok(json);
    }

服务方法很简单;

public List<Installer> GetAppointments(Expression<Func<Installer, bool>> predicate, int? pageSize = null, int? pageIndex = null)
        {
            var results = _context.Installers
                    .Include(x => x.Appointments)
                    .Include(x => x.Appointments.Select(y => y.Driver))
                    .Include(x => x.Appointments.Select(y => y.Vehicle))
                    .Include(x => x.Appointments.Select(y => y.Vehicle.InsurancePolicyVehicles.Select(z => z.Policy)))
                    .Include(x => x.Appointments.Select(y => y.Device))
                    .AsExpandable()
                    .Where(predicate);

            if (pageIndex != null && pageSize != null)
                results = results.Skip((pageIndex.Value - 1) * pageSize.Value).Take(pageSize.Value);

            return results.ToList();

        }

我意识到这有点奇怪，但遗憾的是规范声明他们必须能够从这个角度返回数据。

如果我根据ID过滤掉，它可以正常工作，我会得到过滤后的结果列表。

但是，如果我发送一个政策号码和一个id，请参与部分或完全匹配。我得到了id的整个结果集，并且根据策略编号没有过滤掉它。

有谁能告诉我哪里出错了？