Error Operator && cannot be applied to operands of type int ? & int

Question

Hi

When i add && t.studentid equals t2.studentid then i get above error

public List<View_SessionDeliveryCalendarDetails_Student> GetOrderingInput()
{
List<View_SessionDeliveryCalendarDetails_Student> Result = (from t in context.View_SessionDeliveryCalendarDetails_Students
join t2 in context.View_BookDeliveryDetails
on t.BookID equals t2.BookID && t2.StudentID equals t2.studentid
where t.CurrentStatus == "Due"
orderby t.Name
select t).ToList();
return Result;
}

Thanks

Sachin Singh · Answer

With Linq you can't join on multiple columns like that. Use below code instead public List GetOrderingInput() { List Result = (from t in context.View_SessionDeliver yCalendarDetails_Students join t 2 in context.View_BookDeliverytails on new { t.BookID, t.Studentid } equals new { t 2 .BookID, t 2 .StudentID} where t.CurrentStatus == "Due" orderby t.Name select t).ToList(); return Result; }

Ramco Ramco · Answer

Hi sachin When i write like below then it is showing no error. Both sides int on new { p1 = (int)t.BookID, p2 = (int)t.StudentID} equals new { p1 = (int)t2.BookID, p2 = (int)t2.StudentID } Thanks

Ramco Ramco · Answer

Hi Sachin I will try but the same code it it possible to access fields from t & t2 in aspx page Do i need to change Thanks

Sachin Singh · Answer

Then use properties OK public List GetOrderingInput() { List Result = (from t in context.View_SessionDeliver yCalendarDetails_Students join t 2 in context.View_BookDeliverytails on new {p 1 = t.BookID, p 2 =t.Studentid } equals new {p 1 =(int) t 2 .BookID, p 2 =(int)t 2 .StudentID} where t.CurrentStatus == "Due" orderby t.Name select t).ToList(); return Result; }

Ramco Ramco · Answer

Hi Now it is giving error Invalid Annonymous type member declarator on (int) t2.BookID, (int) t2.StudentID Thanks

Sachin Singh · Answer

Then typecast it List Result = (from t in context.View_SessionDeliveryCalendarDetails_Students join t 2 in context.View_BookDeliveryDetails on new { t.BookID, t.StudentID } equals new {(int) t 2 .BookID, (int) t 2 .StudentID } where t.CurrentStatus == "Due" orderby t.Name select t).ToList(); all 4 should be of same type.

Ramco Ramco · Answer

Hi It is giving error = the type of one of the expressions in join clause is incorrect List Result = (from t in context.View_SessionDeliveryCalendarDetails_Students join t2 in context.View_BookDeliveryDetails on new { t.BookID, t.StudentID } equals new { t2.BookID, t2.StudentID } where t.CurrentStatus == "Due" orderby t.Name select t).ToList(); Thanks