yes, left Join in main query is not required, it is doing nothing but may add duplicate rows.

you can write query like below, removing sub query and adding it in...

I know this is resolved, still....

just a suggetion use a look up table or create another cte for all grades.

Then join this look up table with your main cte (or...

I think there are 3 ways to achieve this in current scenario

1. Increase the size os column [StudentName] to varhcar(400), in [dbo].[StudentDetails] table same as in extended table, trigger...