Error while grouping after a join

I see the following exception

Exception message: 'p.ProductDescription' cannot be converted to SQL.
Stack trace:    in LinqToDB.Linq.Builder.SelectContext.GetMemberExpression(MemberInfo member, Boolean add, Type type, Expression sourceExpression) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 1163
   in LinqToDB.Linq.Builder.SelectContext.ConvertToSql(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 344
   in LinqToDB.Linq.Builder.SelectContext.ConvertToIndexInternal(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 556
   in LinqToDB.Linq.Builder.SelectContext.ConvertToIndex(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 432
   in LinqToDB.Linq.Builder.SubQueryContext.ConvertToSql(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SubQueryContext.cs:riga 100
   in LinqToDB.Linq.Builder.SelectContext.<>c__DisplayClass37_0.<ConvertToSql>b__0(IBuildContext ctx, Expression ex, Int32 l) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 302
   in LinqToDB.Linq.Builder.SelectContext.ProcessScalar[T](Expression expression, Int32 level, Func`4 action, Func`1 defaultAction) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 903
   in LinqToDB.Linq.Builder.SelectContext.ConvertToSql(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 299
   in LinqToDB.Linq.Builder.ExpressionBuilder.ConvertToSql(IBuildContext context, Expression expression, Boolean unwrap) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.SqlBuilder.cs:riga 856
   in LinqToDB.Linq.Builder.ExpressionBuilder.ConvertExpressions(IBuildContext context, Expression expression, ConvertFlags queryConvertFlag) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.SqlBuilder.cs:riga 661
   in LinqToDB.Linq.Builder.SelectContext.ConvertToSql(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 281
   in LinqToDB.Linq.Builder.SelectContext.ConvertToIndexInternal(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 479
   in LinqToDB.Linq.Builder.SelectContext.ConvertToIndex(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 432
   in LinqToDB.Linq.Builder.FirstSingleBuilder.FirstSingleContext.ConvertToIndex(Expression expression, Int32 level, ConvertFlags flags) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\FirstSingleBuilder.cs:riga 276
   in LinqToDB.Linq.Builder.ExpressionBuilder.GetSubQuery(IBuildContext context, MethodCallExpression expr) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.SqlBuilder.cs:riga 238
   in LinqToDB.Linq.Builder.ExpressionBuilder.GetSubQueryContext(IBuildContext context, MethodCallExpression expr) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.QueryBuilder.cs:riga 310
   in LinqToDB.Linq.Builder.ExpressionBuilder.GetSubQueryExpression(IBuildContext context, MethodCallExpression expr, Boolean enforceServerSide) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.QueryBuilder.cs:riga 327
   in LinqToDB.Linq.Builder.ExpressionBuilder.TransformExpression(IBuildContext context, Expression expr, Boolean enforceServerSide) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.QueryBuilder.cs:riga 260
   in LinqToDB.Linq.Builder.ExpressionBuilder.<>c__DisplayClass74_0.<BuildExpression>b__0(Expression expr) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.QueryBuilder.cs:riga 49
   in LinqToDB.Expressions.Extensions.Transform(Expression expr, Func`2 func) in C:\projects\linq2db\Source\LinqToDB\Expressions\Extensions.cs:riga 1353
   in LinqToDB.Expressions.Extensions.<>c__DisplayClass34_0.<Transform>g__Modify|1(MemberBinding b) in C:\projects\linq2db\Source\LinqToDB\Expressions\Extensions.cs:riga 1500
   in LinqToDB.Expressions.Extensions.Transform2[T](ICollection`1 source, Func`2 func) in C:\projects\linq2db\Source\LinqToDB\Expressions\Extensions.cs:riga 1321
   in LinqToDB.Expressions.Extensions.Transform(Expression expr, Func`2 func) in C:\projects\linq2db\Source\LinqToDB\Expressions\Extensions.cs:riga 1546
   in LinqToDB.Linq.Builder.ExpressionBuilder.BuildExpression(IBuildContext context, Expression expression, Boolean enforceServerSide) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.QueryBuilder.cs:riga 49
   in LinqToDB.Linq.Builder.SelectContext.BuildExpression(Expression expression, Int32 level, Boolean enforceServerSide) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 112
   in LinqToDB.Linq.Builder.SelectContext.BuildQuery[T](Query`1 query, ParameterExpression queryParameter) in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\SelectContext.cs:riga 65
   in LinqToDB.Linq.Builder.ExpressionBuilder.Build[T]() in C:\projects\linq2db\Source\LinqToDB\Linq\Builder\ExpressionBuilder.cs:riga 159
   in LinqToDB.Linq.Query`1.CreateQuery(IDataContext dataContext, Expression expr) in C:\projects\linq2db\Source\LinqToDB\Linq\Query.cs:riga 280
   in LinqToDB.Linq.Query`1.GetQuery(IDataContext dataContext, Expression& expr) in C:\projects\linq2db\Source\LinqToDB\Linq\Query.cs:riga 233
   in LinqToDB.Linq.ExpressionQuery`1.GetQuery(Expression& expression, Boolean cache) in C:\projects\linq2db\Source\LinqToDB\Linq\ExpressionQuery.cs:riga 84
   in LinqToDB.Linq.ExpressionQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() in C:\projects\linq2db\Source\LinqToDB\Linq\ExpressionQuery.cs:riga 179
   in System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   in System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   in Import2TSS.Alerting.ComputPLInternal(DataConnection db, Action`1 Log, Nullable`1 cargoid) in C:\compliance\MAR_Reporting_API_Sourcing\OilPhysical_ImportCsv2DB\DB\Alerting.cs:riga 635
   in Import2TSS.Alerting.Detect(Action`1 Log, String ConnName, DateTime asofDate) in C:\compliance\MAR_Reporting_API_Sourcing\OilPhysical_ImportCsv2DB\DB\Alerting.cs:riga 844

Steps to reproduce

after the code

var queryTotCosts =
            from c in db.GetTable<Cost>()
            join n in db.GetTable<NominationValid>()
                on new
                {
                    c.CargoID,
                    c.DeliveryID,
                    c.DealNumber,
                    c.ParcelID
                } equals new
                {
                    n.CargoID,
                    n.DeliveryID,
                    DealNumber = n.DeliveryDealNumber > 0 ? n.DeliveryDealNumber : n.ReceiptDealNumber,
                    ParcelID = n.DeliveryDealNumber > 0 ? n.DeliveryParcelID : n.ReceiptParcelID
                }
            join t in db.GetTable<TradeValid>()
                on new { c.DealNumber, c.ParcelID } equals new { t.DealNumber , t.ParcelID }
            where c.OperationType != Cost.Operations.Delete.GetEnumDescription() && 
                  (cargoid == null || c.CargoID == cargoid)
            group new { c.FeePV, n.ProductDescription, t.PortfolioName } 
                by new { n.CargoID, c.Currency ,c.PayRec, n.TitleTranfertDate} into cargoGr
            select new CostTotal
            {
                CargoID = cargoGr.Key.CargoID,
                PayRec = cargoGr.Key.PayRec,
                TotAmount = cargoGr.Sum(cst => cst.FeePV),
                Currency = cargoGr.Key.Currency,
                TitleTransferDate = cargoGr.Key.TitleTranfertDate,
                Commodity = cargoGr.FirstOrDefault().ProductDescription,
                Portfolio = cargoGr.FirstOrDefault().PortfolioName
            };
var totCosts = queryTotCosts.ToArray();

Environment details

linq2db version: 2.5.4.0 Database Server: Ms Sql 2016 Operating system: Windows 7 Framework version: *.NET Framework 4.5.2

[sdanyliv]

~Maybe you have to add booking_company into partition?~

Good 😃

[giuliohome]

I hopefully see… the problem is that I have multiple title transfer dates… Ok, your suggestion was really key! Thank you! It’s enough from your side, the issue is more in the assumptions of the functional logic. Thanks again.