SQL help: Selecting tickets with no open tasks

Question

Hi Gurus,
I'm new to SQL. I need your help in a script where I need to fetch the tickets with no open tasks.
Say, following is the Task table
Table: Task
| ticketid | taskid | taskstatus |
| 1 | 1 | O |
| 1 | 2 | O |
| 1 | 3 | O |
| 2 | 4 | C |
| 2 | 5 | C |
| 3 | 6 | C |
| 3 | 7 | O |
The query should return the ticketid(s) with all its taskstatus = 'C'.
Any help would be highly appreciated.
Thanks

Answer 1

Hi Surya,
Here's an Oracle style example (Sorry, I just can't do that ansi stuff)
SQL> with ticket as (select 1 ticketid, 'C' reason from dual union all
                select 2 ticketid, 'O' reason from dual union all
                select 3 ticketid, 'O' reason from dual union all
                select 4 ticketid, 'C' reason from dual)
,taskstatus as (select 1 taskstatusid, 'O' taskstatus from dual union all
                select 2 taskstatusid, 'C' taskstatus from dual union all
                select 3 taskstatusid, 'P' taskstatus from dual union all
                select 4 taskstatusid, 'F' taskstatus from dual union all
                select 5 taskstatusid, 'O' taskstatus from dual union all
                select 6 taskstatusid, 'C' taskstatus from dual union all
                select 7 taskstatusid, 'P' taskstatus from dual union all
                select 8 taskstatusid, 'F' taskstatus from dual)
      ,task as (select 1 ticketid,  1 taskid, 2 taskstatusid from dual union all
                select 1 ticketid,  2 taskid, 3 taskstatusid from dual union all
                select 1 ticketid,  3 taskid, 4 taskstatusid from dual union all
                select 1 ticketid,  4 taskid, 4 taskstatusid from dual union all
                select 2 ticketid,  5 taskid, 1 taskstatusid from dual union all
                select 2 ticketid,  6 taskid, 1 taskstatusid from dual union all
                select 2 ticketid,  7 taskid, 1 taskstatusid from dual union all
                select 3 ticketid,  8 taskid, 2 taskstatusid from dual union all
                select 3 ticketid,  9 taskid, 2 taskstatusid from dual union all
                select 3 ticketid, 10 taskid, 6 taskstatusid from dual union all
                select 4 ticketid, 11 taskid, 2 taskstatusid from dual union all
                select 4 ticketid, 12 taskid, 6 taskstatusid from dual union all
                select 4 ticketid, 13 taskid, 4 taskstatusid from dual union all
                select 4 ticketid, 14 taskid, 8 taskstatusid from dual)
select a.ticketid, c.taskstatus
  from  task a, ticket b, taskstatus c
where a.ticketid = b.ticketid
   and c.taskstatusid = a.taskstatusid
   and (c.taskstatus = 'C' or c.taskstatus = 'F')
   and b.reason = 'C'     
   and not exists (select null
                     from task a1, taskstatus c1
                    where a1.ticketid = a.ticketid
                      and c1.taskstatusid = a1.taskstatusid
                      and (c1.taskstatus = 'O' or c1.taskstatus = 'P'))
order by 1,2
  TICKETID T
         4 C
         4 C
         4 F
         4 F
4 rows selected.Please note, how I made test data, that way is much more helpful than your tables
Regards
Peter