update query with case statement

I'm slowly learning SQL on a need to know basis.  I needed to do a
conditional update so I tried the case statement.  My query looks like this:

update &file
set field1 = case when (field2 = '0')     
                     then 'Final Totals'  
                when (field2 = '1')     
                     then 'Store Totals'  
                else field1                 
                end                       

Works great interactively with the substitution variable, but dies in batch
with a message that says: " Message . . . . :   Global variable prompting is
not allowed in batch mode.  Cause . . . . . :   You tried to use the
variable                             
   "file                          " before it was set.  Prompting for
variables
   cannot be done in batch mode. "  It goes on to advise using the setvar
parm, which I did in the CL.  The strqmqry statement was:

  DCL        VAR(&UPDFILE) TYPE(*CHAR) LEN(20) +  
               VALUE('LIBRARY/FILENAME')         
  STRQMQRY   QMQRY(QRYNAME) SETVAR((FILE +        
               &UPDFILE))
              

If I run a query with substitution variables defined as above in batch
something like :

update &file set &set where &where

it works fine.  

My workaround was to hard code the file name in the query.  Am I doing
something wrong?