Subqueries and Case

Question

I have two codes - A & B
My question is can I use code B i.e Case statement as a subquery of code A to get the necessary output
=============================CODE A=====================================================
select a.search_code,a.name,a.total as "Total Service Calls",decode(b.total_adjusted_miss,null,0,b.total_adjusted_miss) "Missed SLA (Adjusted)",
decode(c.total_unadjusted_miss,null,0,c.total_unadjusted_miss) "Missed SLA (UnAdjusted)",
decode(round(((a.total - b.total_adjusted_miss)/a.total)*100,2),null,100,round(((a.total - b.total_adjusted_miss)/a.total)*100,2)) "Total Adjusted Yield %",
decode(round(((a.total - c.total_unadjusted_miss)/a.total)*100,2),null,100,round(((a.total - c.total_unadjusted_miss)/a.total)*100,2)) "Total UnAdjusted Yield %"
from (
(SELECT
count(*) as total,
sg.search_code,
sg.NAME
FROM
task t,
operational_process op,
support_group sg,
person p
where sg.support_group_seq_id in (SELECT sg2.support_group_seq_id FROM support_group sg2
start with sg2.SEARCH_CODE = p_target_name
connect by prior sg2.support_group_seq_id=sg2.parent_support_group_seq_id)
and t.task_seq_id = op.task_seq_id
and t.task_seq_id = op.task_seq_id
and sg.support_group_seq_id = op.support_group_seq_id
and op.assigned_person_seq_id = p.person_seq_id
and sg.search_code = p_target_name
and t.task_type in ('Inc')
and to_char(op.est_actual_end_datetime, 'MM-YYYY') = '02-2012'
and t.priority is not null
group by sg.search_code, sg.name
))a,
=============================CODE B=====================================================
Select t.task_number, CASE
WHEN ((T.PRIORITY like ('%Immediate%')) AND
(OP._ACTUAL_END_DATETIME - OP._ACTUAL_START_DATETIME) * 24 < 2) THEN
1
WHEN ((T.PRIORITY like ('%Critical%')) AND
(OP._ACTUAL_END_DATETIME - OP._ACTUAL_START_DATETIME) * 24 < 4) THEN
1
WHEN ((T.PRIORITY like ('%Urgent%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL <= 24) THEN
1
WHEN ((OP.PRIORITY like ('%Medium%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL <= 120) THEN
1
WHEN ((T.PRIORITY like ('%Normal%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL <= 72) THEN
1
ELSE
0
END W2W_SLA,
CASE
WHEN ((T.PRIORITY like ('%Immediate%')) AND
((OP._ACTUAL_END_DATETIME - OP._ACTUAL_START_DATETIME) * 24) -
NVL(OP.EXCEPTION_DUR_HOURS_DEC, 0) <= 2) THEN
1
WHEN ((T.PRIORITY like ('%Critical%')) AND
((OP._ACTUAL_END_DATETIME - OP._ACTUAL_START_DATETIME) * 24) -
NVL(OP.EXCEPTION_DUR_HOURS_DEC, 0) <= 4) THEN
1
WHEN ((T.PRIORITY like ('%Urgent%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL -
NVL(OP.EXCEPTION_DUR_HOURS_DEC, 0) <= 24) THEN
1
WHEN ((T.PRIORITY like ('%Medium%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL -
NVL(OP.EXCEPTION_DUR_HOURS_DEC, 0) <= 120) THEN
1
WHEN ((T.PRIORITY like ('%Normal%')) AND
OP.ACTUAL_DUR_HOURS_DECIMAL -
NVL(OP.EXCEPTION_DUR_HOURS_DEC, 0) <= 72) THEN
1
ELSE
0
END W2W_SLA_EXCEPTION
from task t, operationalprocess OP, support_group s
where t.task_seq_id = op.task_seq_id
and t.task_type in ('Inc', 'SR')
and op.support_group_seq_id = s.support_group_seq_id
--and s.name = 'L3 Service Management Data Warehouse Development'
and to_char(t._actual_end_datetime, 'MM-YYYY') = '02-2012'

Answer 1

Hello
I'm not quite clear on what you're asking. You want to know if it's possible to put query A in a subquery so you can access the columns to use in query b?
If so, a subquery wouldn't be a particularly efficient way of doing it as you would need to repeat it for each attribute. Instead you could use an inline view something like so (bear in mind I don't have your tables or data so I can't test whether this even runs!)
SELECT t.task_number,
      CASE
          WHEN ((t.priority LIKE ('%Immediate%')) AND
               (op._actual_end_datetime - op._actual_start_datetime) * 24 < 2) THEN
           1
          WHEN ((t.priority LIKE ('%Critical%')) AND
               (op._actual_end_datetime - op._actual_start_datetime) * 24 < 4) THEN
           1
          WHEN ((t.priority LIKE ('%Urgent%')) AND op.actual_dur_hours_decimal <= 24) THEN
           1
          WHEN ((op.priority LIKE ('%Medium%')) AND op.actual_dur_hours_decimal <= 120) THEN
           1
          WHEN ((t.priority LIKE ('%Normal%')) AND op.actual_dur_hours_decimal <= 72) THEN
           1
          ELSE
           0
      END w2w_sla,
      CASE
          WHEN ((t.priority LIKE ('%Immediate%')) AND ((op._actual_end_datetime - op._actual_start_datetime) * 24) -
               nvl(op.exception_dur_hours_dec, 0) <= 2) THEN
           1
          WHEN ((t.priority LIKE ('%Critical%')) AND ((op._actual_end_datetime - op._actual_start_datetime) * 24) -
               nvl(op.exception_dur_hours_dec, 0) <= 4) THEN
           1
          WHEN ((t.priority LIKE ('%Urgent%')) AND
               op.actual_dur_hours_decimal - nvl(op.exception_dur_hours_dec, 0) <= 24) THEN
           1
          WHEN ((t.priority LIKE ('%Medium%')) AND
               op.actual_dur_hours_decimal - nvl(op.exception_dur_hours_dec, 0) <= 120) THEN
           1
          WHEN ((t.priority LIKE ('%Normal%')) AND
               op.actual_dur_hours_decimal - nvl(op.exception_dur_hours_dec, 0) <= 72) THEN
           1
          ELSE
           0
      END w2w_sla_exception
FROM   _task t,
       operational_process op,
       support_group s,
       (SELECT a.search_code,
               a.NAME,
               a.total AS "Total Service Calls",
               decode(b.total_adjusted_miss, NULL, 0, b.total_adjusted_miss) "Missed SLA (Adjusted)",
               decode(c.total_unadjusted_miss, NULL, 0, c.total_unadjusted_miss) "Missed SLA (UnAdjusted)",
               decode(round(((a.total - b.total_adjusted_miss) / a.total) * 100, 2)
                     ,NULL
                     ,100
                     ,round(((a.total - b.total_adjusted_miss) / a.total) * 100, 2)) "Total Adjusted Yield %",
               decode(round(((a.total - c.total_unadjusted_miss) / a.total) * 100, 2)
                     ,NULL
                     ,100
                     ,round(((a.total - c.total_unadjusted_miss) / a.total) * 100, 2)) "Total UnAdjusted Yield %"
        FROM   ((SELECT COUNT(*) AS total, sg.search_code, sg.NAME
                 FROM   task t, operational_process op, support_group sg, person p
                 WHERE  sg.support_group_seq_id IN
                        (SELECT sg2.support_group_seq_id
                         FROM   support_group sg2
                         START  WITH sg2.search_code = p_target_name
                         CONNECT BY PRIOR sg2.support_group_seq_id = sg2.parent_support_group_seq_id)
                 AND    t.task_seq_id = op.task_seq_id
                 AND    t.task_seq_id = op.task_seq_id
                 AND    sg.support_group_seq_id = op.support_group_seq_id
                 AND    op.assigned_person_seq_id = p.person_seq_id
                 AND    sg.search_code = p_target_name
                 AND    t.task_type IN ('Inc')
                 AND    to_char(op.est_actual_end_datetime, 'MM-YYYY') = '02-2012'
                 AND    t.priority IS NOT NULL
                 GROUP  BY sg.search_code, sg.NAME)) a
        ) query_a
WHERE  t.task_seq_id = op.task_seq_id
AND    t.task_type IN ('Inc', 'SR')
AND    op.support_group_seq_id = s.support_group_seq_id
     --and s.name = 'L3 Service Management Data Warehouse Development'
AND    to_char(t._actual_end_datetime, 'MM-YYYY') = '02-2012'
AND
       query_a.search_code = s.search_code
AND
       query_a.NAME = s.NAMEI've put the join between the two queries as being on support_group.name and support_group.search_code. If you need to join on additional columns, you would need to include them in the inline view for query a (including group by) and add them to the join.
If that's not what you meant, maybe you could explain a bit more.
HTH
David