public IEnumerable<JobAdPostVM> GetAds(JobAdFilterVM vm, List<JobAdPostVM> pagedJobAdPostVMs)
{
    if (vm.Place != null)
    {
         var place = JobCategoryUnitOfWork.Places.SingleOrDefault(m => m.Name == vm.Place);
         var placeId = place == null ? (int?) null : place.PlaceId;
    }

    if (vm.ContractType != null)
    {
        var contractType = JobCategoryUnitOfWork.ContractTypes.SingleOrDefault(m => m.Name == vm.ContractType);
        var contractTypeId = contractType == null ? (int?)null : contractType.ContractTypeId;
    }

    return null;
}

public class JobPostCategoryUnitOfWork : IJobPostCategoryUnitOfWork
{
    private readonly DataContext Context;
    public IPlaceRepository Places { get; }
    public IContractTypeRepository ContractTypes { get; }

    public JobPostCategoryUnitOfWork(DataContext context)
    {
        this.Context = context;
        Places = new PlaceRepository(context);
        ContractTypes = new ContractTypeRepository(context);
    }
}

var primarykey = getKey(JobCategoryUnitOfWork.Places, m => m.Name == vm.Place);