Having  ( ) and & in the values

You could try this workaround, which works for me on the HR.EMPLOYEES table after inserting a new employee with

EMPLOYEE_ID = 2207

LAST_NAME = 'SUPT (COPY & SORT FILES)'

Using this query (I altered your text string to fit it into the LAST_NAME column)...

select (

   case when last_name= 'book' then 1

        when last_name='SUPT (COPY' || ' & ' || 'SORT FILES)' then 2

        else null

   end

) as result

from employees

where employee_id > 2000;

The output is...

----------

I did my test on 4.1.1.19.59 with no login script specified in Tools > Preferences > Database > Filename for connection startup script, as noted in discussions like

startup script and substitution variables (ampersand)

Do you have that version installed and do not specify a login script?  If so, and you followed the code example, then I am not sure what may be going in your case.

Edit:  Also checked behavior in upcoming patch / development versions.  There is no change (only checked for the case of no login script).  Workaround the only way to go.