Linq查询不会让我按日期订购

Question

I have the following LINQ query -

var data = (from req in db.tblRequirements
       where req.guidRequirementId == guidRequirementId
             && (!db.ViewMIPRAlls.Any(x=>x.guidRequirementId == req.guidRequirementId))
       select new
       {
           guidRequirementId = req.guidRequirementId,
           strStatus = req.tblCodesRequirementStatus.strDescription,
           strNumber = req.ViewNumber.strAwardNumber,
           strOffice = req.tblOrganization.strAcronym,
           strCustomerOffice = req.tblOrganizationCustomer.strAcronym,
           strDescription = req.strDescription,
           strNotes = req.strNotes,
           strStatusId = req.strStatusId,
           strCompany = req.strCompany,
           strUpdatedBy = Person.GetPersonNameFromUserID(req.guidUserId),
           dtmUpdated = Requirement.UpdateTime(req.guidRequirementId),
           dtmEsitmatedEnd = (req.tblDates.Select(x=>x.dtmEnd) != null
              ? req.tblDates.Select(x=>x.dtmEnd.ToShortDateString()).ToString()
              : ""
           )
       }).OrderBy(x=>x.dtmEnd);

and I am unable to order it by date. This query results in the following error:

Could not format node 'ClientQuery' for execution as SQL.

Answer 1

选择之前的Orderby或通过选择中创建的东西进行Orderby

Answer 2

The OrderBy clause should come before the select new if you try to sort by fields in SQL.

Your LINQ statement could be transformed in:

var data = 
    from req in db.tblRequirements
    from dates in req.tblDates
    where req.guidRequirementId == guidRequirementId
         && (!db.ViewMIPRAlls.Any(x=>x.guidRequirementId == req.guidRequirementId))
    order by dates.dtmEnd
    select new
    {
        guidRequirementId = req.guidRequirementId,
        strStatus = req.tblCodesRequirementStatus.strDescription,
        strNumber = req.ViewNumber.strAwardNumber,
        strOffice = req.tblOrganization.strAcronym,
        strCustomerOffice = req.tblOrganizationCustomer.strAcronym,
        strDescription = req.strDescription,
        strNotes = req.strNotes,
        strStatusId = req.strStatusId,
        strCompany = req.strCompany,
        strUpdatedBy = Person.GetPersonNameFromUserID(req.guidUserId),
        dtmUpdated = Requirement.UpdateTime(req.guidRequirementId),
        dtmEsitmatedEnd = (req.tblDates.Select(x=>x.dtmEnd) != null
            ? req.tblDates.Select(x=>x.dtmEnd.ToShortDateString()).ToString()
            : ""
        )
    }

Please note that depending on the type of relationship between tblRequirements and tblDates , this may yield more records than your initial select. To overcome this, you'll need to think of a way to aggregate the records in tblDates corresponding to a tblRequirements record (perhaps just take max(tblDates.dtmEnd) ?)

Answer 3

Try:

where req.guidRequirementId == guidRequirementId
        && (!db.ViewMIPRAlls.Any(x=>x.guidRequirementId == req.guidRequirementId))
order by req.dtmEnd     
select new