添加额外的linq where子句基于变量

Question

我正在尝试向linq查询添加其他where子句,具体取决于传递给函数的变量结果.

var allFeedback = 
    from f in _unitOfWork.Feedback.All()
    join b in _unitOfWork.Bookings.All() on f.CourseBookingID equals b.CourseBookingID
    join cb in _unitOfWork.CourseBookings.All() on f.CourseBookingID equals cb.CourseBookingID
    where b.SiteID == siteID && b.Date >= fromDate && b.Date <= to && b.CancelledID == null
    select f;

if (courseID > 0)
{
    allFeedback.Where(f => f.CourseBooking.CourseID == courseID);
}

if (facilitatorID == 0)
{
    allFeedback.Where(f => f.CourseBooking.FacilitatorID == null);
}
else if (facilitatorID > 0)
{
    allFeedback.Where(f => f.CourseBooking.FacilitatorID == facilitatorID);
}

allFeedback.ToList();

我想将where子句添加到原始查询"allFeedback",但是当执行查询时,将忽略其他子句.

这可能吗？

Answer 1

是的它可能只做:

if (courseID > 0)
{
    allFeedback = allFeedback.Where(f => f.CourseBooking.CourseID == courseID);
}

if (facilitatorID == 0)
{
    allFeedback = allFeedback.Where(f => f.CourseBooking.FacilitatorID == null);
}
else if (facilitatorID > 0)
{
    allFeedback = allFeedback.Where(f => f.CourseBooking.FacilitatorID == facilitatorID);
}

您只是忘了将结果分配给变量.