The text data type cannot be selected as DISTINCT because it is not comparable

任何方式来解决这个问题而不改变数据类型？

这是我的linq语句(很长)：

var query = (from s in db.tblSuppliers
                             join p in
                                 (
                                    from p1 in db.tblSupplierPricingSchemes
                                    select new
                                    {
                                        p1.SupplierID,p1.PSLangPairID,p1.CustomerID,p1.PSLanguageStatus,p1.PSPriceBasis,p1.PSMinFlatCharge,p1.PSTrxPrf,p1.PSNoMatch,p1.PSFuzzy,p1.PS100Match_Rep,p1.PSTrxOnly,p1.PSPrfOnly,p1.PSLinquisticHourlyRate,p1.PSDTPType,p1.PSDTPRate,p1.PS_FZ50,p1.PS_FZ75,p1.PS_FZ85,p1.PS_FZ95,p1.PS_FZ100,p1.PS_FZREPS,p1.PSPerfectMatch
                                    }
                                 ) on s.SupplierID equals p.SupplierID
                             join p2 in
                                 (
                                        from p in db.tblSupplierPricingSchemes
                                        where custID.Contains(p.CustomerID) && p.PSLangPairID == languagePairID
                                        group p by new { p.SupplierID,p.PSLangPairID,p.PSPriceBasis } into g
                                        let CustomerID = g.Max(uh => uh.CustomerID)
                                        select new
                                        {
                                            g.Key.SupplierID,g.Key.PSLangPairID,g.Key.PSPriceBasis,CustomerID
                                        }
                                 ) on p.SupplierID equals p2.SupplierID
                             join b in db.tblPricingBasis on p.PSPriceBasis equals b.PricingBasisID
                             join ss in db.tblSupplierStatus on p.PSLanguageStatus equals ss.SupplierStatusID into g1
                             from ss in g1.DefaultIfEmpty()
                             join l in db.tblLangPairs on p.PSLangPairID equals l.ProductID
                             where l.ProductID == languagePairID
                                && p.PSLangPairID == p2.PSLangPairID
                                && p.CustomerID == p2.CustomerID
                                && p.PSPriceBasis == p2.PSPriceBasis
                             select new PreferredSupplier
                             {
                                 SupplierID = s.SupplierID,//SupplierName = s.CompanyName != null ? s.CompanyName + "-" + s.SupplierFirstName + " " + s.SupplierLastName
                                 //                                     : s.SupplierFirstName + " " + s.SupplierLastName,SupplierName = s.CompanyName != null
                                            ? s.SupplierFirstName != null || s.SupplierLastName != null
                                                    ? s.CompanyName + "-" + s.SupplierFirstName + " " + s.SupplierLastName
                                                    : s.CompanyName
                                            : s.SupplierFirstName + " " + s.SupplierLastName,CompanyName = s.CompanyName,SupplierFirstName = s.SupplierFirstName,SupplierLastName = s.SupplierLastName,SupplierStatus = p.CustomerID == customerID ? "Team Member" : ss.SupplierStatus,Email = (string)s.SupplierEmails,Rate = (s.VolumeDiscountType == 1 ? // Percentage
                                     //if the volume discount is as percentage then get the rate and multiple it by 1 - the discount percentage
                                        ((words > s.VolumeDiscountAmount && (task == "TM No Match" || task == "Translation/Proofreading")) ? 1 - s.VolumeDiscountValue : 1) *
                                                    (
                                                        rateField == "PSTrxPrf" ? p.PSTrxPrf :
                                                        rateField == "PSNoMatch" ? p.PSNoMatch :
                                                        rateField == "PSFuzzy" ? p.PSFuzzy :
                                                        rateField == "PS100Match_Rep" ? p.PS100Match_Rep :
                                                        rateField == "PSLinquisticHourlyRate" ? p.PSLinquisticHourlyRate :
                                                        rateField == "PSDTPRate" ? p.PSDTPRate :
                                                        rateField == "PS_FZ50" ? p.PS_FZ50 :
                                                        rateField == "PS_FZ75" ? p.PS_FZ75 :
                                                        rateField == "PS_FZ85" ? p.PS_FZ85 :
                                                        rateField == "PS_FZ95" ? p.PS_FZ95 :
                                                        rateField == "PS_FZ100" ? p.PS_FZ100 :
                                                        rateField == "PS_FZREPS" ? p.PS_FZREPS :
                                                        rateField == "PSPerfectMatch" ? p.PSPerfectMatch : null
                                                    ) :
                                     // Discount in Amount
                                     // Take the Rate and substract the amount to discount
                                                   (
                                                        rateField == "PSTrxPrf" ? p.PSTrxPrf :
                                                        rateField == "PSNoMatch" ? p.PSNoMatch :
                                                        rateField == "PSFuzzy" ? p.PSFuzzy :
                                                        rateField == "PS100Match_Rep" ? p.PS100Match_Rep :
                                                        rateField == "PSLinquisticHourlyRate" ? p.PSLinquisticHourlyRate :
                                                        rateField == "PSDTPRate" ? p.PSDTPRate :
                                                        rateField == "PS_FZ50" ? p.PS_FZ50 :
                                                        rateField == "PS_FZ75" ? p.PS_FZ75 :
                                                        rateField == "PS_FZ85" ? p.PS_FZ85 :
                                                        rateField == "PS_FZ95" ? p.PS_FZ95 :
                                                        rateField == "PS_FZ100" ? p.PS_FZ100 :
                                                        rateField == "PS_FZREPS" ? p.PS_FZREPS :
                                                        rateField == "PSPerfectMatch" ? p.PSPerfectMatch : null
                                                     ) - (s.VolumeDiscountValue == null ? 0 : s.VolumeDiscountValue)),//PSMinFlatCharge = p.PSMinFlatCharge,MinimumFee = p.PSMinFlatCharge,//Basis = b.PricingBasisDesc,Basis = task == "DTP" || task == "DTP Edit" ? p.PSDTPType : b.PricingBasisDesc,StatusOrder = p.CustomerID == customerID ? 0 : p.PSLanguageStatus == null ? 1000 : p.PSLanguageStatus
                             }).Distinct();