Question

I have problem with my SQL query

I have

T1:

ID    STATUS   REPORTEDBY  
1     CLOSED   USER1
2     CLOSED   USER2
3     NEW      USER1
4     INPRG    USER1
5     CLOSED   USER1

T2:

T1ID  STATUS
1     NEW
1     CHECKING
1     CLOSED

2     NEW
2     CHECKING
2     CLOSED


3     NEW

4     CHECKING
4     INPRG 

5     INPRG
5     CLOSED

As result I want to get this:

USER    NumberHasCHECKING  NumberDifferentFromNewChecking  NumberClosed

USER1          2                         3                      2
USER2          1                         1                      1

I want to get as result group by REPORTEDBY field

1. number of records from T1 for which exist CHECKING status in T2,

2. number of records from T1 which is now in status differentg from NEW or CHECKING in T1

3. and number of records in T1 which is currently in CLOSED status in T1.

.

select reportedby,count (case when T2.status='CHECKING' then 1 end) as NumberHasChecking,
count (case when T2.status not in ('NEW','CHECKING') then 1 end) as NumberDifferentFromNewChecking, 
count (case when T1.status='CLOSED' then 1 end) as  NumberClosed
from t1
inner join t2 on T1.ID=T2.T1ID
group by reportedby

but after I do inner join I am getting much greater result for second and third column.
How to solve this?
thank you

Answer 1

Not sure if this will work on DB2:

Select 
  ReportedBy,
  Count (Case When t2.Status = 'CHECKING' Then 1 End) As NumberHasChecking,
  Count (Distinct Case When t1.Status Not In ('NEW','CHECKING') Then t1.Id End) As NumberDifferentFromNewChecking, 
  Count (Distinct Case When t1.Status = 'CLOSED' Then t1.Id End) As NumberClosed
From
  t1
    Inner Join
  t2
    on t1.Id = t2.t1Id
Group By 
  ReportedBy