Getting error update using decode

Question

Hi Gurus,
Your help is greatly appreciated.
Iam having issue with decode using in the below update statement,
Can anyone please help what am missing here.
    varSTMT := 'UPDATE PROD.PROCESS_COUNTER ';
    varSTMT := varSTMT ||'SET LAST_COUNT_ADDED =  ' decode('trunc(change_date), trunc(sysdate),last_count_added+1,1) ' ';
     varSTMT := varSTMT ||' WHERE PROCESS_NAME = ''DAILY_FILE''';

Answer 1

It is not clear what your update statement should look like, but quotes are definitely messed up. Assuming update should be:
UPDATE PROD.PROCESS_COUNTER SET LAST_COUNT_ADDED =  decode(trunc(change_date), trunc(sysdate),last_count_added+1,1)  WHERE PROCESS_NAME = 'DAILY_FILE'
change:
varSTMT := varSTMT ||'SET LAST_COUNT_ADDED =  ' decode('trunc(change_date), trunc(sysdate),last_count_added+1,1) ' ';
to
varSTMT := varSTMT ||'SET LAST_COUNT_ADDED = decode(trunc(change_date),trunc(sysdate),last_count_added+1,1)';
SY.