Conditional where

Question

Hi,
I have a below query.In last condition (ie. AND sb.timezone in )i have to pass 0 when sa.timezone_subject is null
elae i have to pass (1,2).
for ex if  sa.timezone_subject is null then
the last condition should be
AND sb.timezone in(0)
else sb.timezone in(1,2)
query
select sa.timezone_subject,sb.*
from subject_availability sa,SUBJECT_BOUNDARIES sb
where sa.year= sb.year
and sa.month  = sb.month
and sa.subject =sb.subject
and sa.subject_option=sb.subject_option
and sa.lvl = sb.lvl
and sa.YEAR = 2011
  AND     sa.MONTH = 'MAY'
  AND     sa.SUBJECT = 'BIOLOGY'
  AND     sa.SUBJECT_OPTION = 'BIOLOGY'
  AND     sa.LVL = 'HL'
  AND     sa.language = 'ENGLISH'
  AND sb.timezone in()and i have tried using case but it does't worked out please advice

Answer 1

HI,
select sa.timezone_subject,sb.*
from subject_availability sa,SUBJECT_BOUNDARIES sb
where sa.year= sb.year
and sa.month  = sb.month
and sa.subject =sb.subject
and sa.subject_option=sb.subject_option
and sa.lvl = sb.lvl
and sa.YEAR = 2011
  AND     sa.MONTH = 'MAY'
  AND     sa.SUBJECT = 'BIOLOGY'
  AND     sa.SUBJECT_OPTION = 'BIOLOGY'
  AND     sa.LVL = 'HL'
  AND     sa.language = 'ENGLISH'
  AND     (   sa.timezone_subject is null AND sb.timezone in(1)
           OR sb.timezone in(2,3)
{code}
Regards.
Al