Query works on Oracle 11g but fails on Oracle 8i

Question

I am running this query in Oracle 11g with no problem:

select (case
         when seqnum = 1 then
          \'1\'
         when seqnum = cnt then
          \'0\'         


        

Answer 1

OK - trip--down-memory-lane time:

select decode(seqnum,
                1,    '1',
                cnt,  '0') as value1,
       decode(seqnum,
                1,    t.BEGIN_DT,
                cnt,  t.END_DT) as TIME1,      
       t4.UNIT1 || '.SUBBATCH_TRIGGER' TAG     
  from (select t.*,
               row_number() over (partition by t.BATCH_ID, t.plant_unit, t3.ID2
                                  order by t.BEGIN_DT) as seqnum,
               count(*) over (partition by t.BATCH_ID, t.plant_unit, t3.ID2) as cnt
          from SCH2.tb_pg_unit_stap t
          INNER join (select ID1, batch_id
                        from SCH2.VW_BATCH) t2
            on t.BATCH_ID = t2.BATCH_ID
          INNER join (select ID2, ID1
                        from SCH1.STEP) t3
            on t3.ID1 = t2.ID1) t
  INNER join SCH2.TB_W_MACHINE t4
    on t4.plant_unit = t.plant_unit
  where (seqnum = 1 or seqnum = cnt) AND
        (t.BEGIN_DT > '01-jan-2013' AND t.BEGIN_DT < '01-feb-2013');

Answer 2

AFAK case command was introduced since 9i.