Question

I have a SQL query which selects some values (and works across tables in the form of a join). One of the fields returns 0 or 1 but I want to return something else in the case of 0, or the case of 1 (yes/no).

The code:

SELECT Passed, 
       CASE Passed
            WHEN '1' THEN 'Yes'
            ELSE 'No'
       END
FROM EXAM_INSTANCE

Works perfectly well.

But when I integrate this as a sub-query in the stored proc, I get the error:

Only one expression can be specified in the select list when the sub-query is not introduced with EXISTS.

The original query is:

select Firstname, Lastname, ei.Started, 
       ((ei.totalcorrect*100)/@examQuestionCount) as percentage, passed, ei.InstanceID
from ea ei, INVITE i, OSTTable ost, f f
where ei.Finished is not null
      and ei.InviteID = i.InviteID 

I am trying:

   select Firstname, Lastname, ei.Started, 
          ((ei.totalcorrect*100)/@examQuestionCount) as percentage, 
   (SELECT Passed, 
           CASE Passed
                WHEN '1' THEN 'Yes'
                ELSE 'No'
           END
     FROM EA), 
     ei.InstanceID
 from EA E ei, INVITE i, osttable ost, ef e
 where ei.Finished is not null
       and ei.InviteID = i.InviteID 

What is the cause for my error?

PS I’ve changed table names for privacy reasons so don’t worry if they don’t match up.

Answer 1

select Firstname, Lastname, ei.Started, 
          ((ei.totalcorrect*100)/@examQuestionCount) as percentage,
           passed_ = CASE Passed
                WHEN '1' THEN 'Yes'
                ELSE 'No'
           END,
     ei.InstanceID
 from EA E ei, INVITE i, osttable ost, ef e
 where ei.Finished is not null
       and ei.InviteID = i.InviteID