Question

I have an issue where my SQL query will not get rid of null values.

I have tried a myriad of different techniques, but I am a novice.

My desired result is an Order number followed by the date which the status occurs all in one line.

select mo.order_id OrderID,
case when osr.order_status_cd = 120 and osr.create_date is not null then    osr.create_date end as POCreated,
case when osr.order_status_cd = 220 and osr.create_date is not null then osr.create_date end as Ordered,
case when osr.order_status_cd = 300 and osr.create_date is not null then osr.create_date end as Shipped,
case when osr.order_status_cd = 400 and osr.create_date is not null then osr.create_date end as Received,
case when osr.order_status_cd = 500 and osr.create_date is not null then    osr.create_date end as Completed,
from order_status_record osr
inner join msorder mo on mo.order_id = osr.msorder_id

Instead of getting results that look like this:

OrderID POCreated   Ordered     Shipped      Received    Completed
497822  11/18/2012  NULL          NULL        NULL        NULL
497822  NULL       11/19/2012     NULL        NULL        NULL
497822  NULL        NULL       11/19/2012     NULL        NULL
497822  NULL        NULL          NULL     11/19/2012     NULL
497822  NULL        NULL          NULL        NULL     11/19/2012

I want this:

OrderID POCreated   Ordered     Shipped      Received    Completed
497822  11/18/2012  11/19/2012  11/19/2012   11/19/2012  11/19/2012

Do I need to create a virtual table? Do I need an if function? Why do the Nulls still populate?

Any help would be much appreciated.

Thanks,

Andrew

Answer 1

If you add an aggregate function to each of the CASE statements and then a GROUP BY the records will consolidate into a single row:

select mo.order_id OrderID,
  max(case when osr.order_status_cd = 120 and osr.create_date is not null then osr.create_date end) as POCreated,
  max(case when osr.order_status_cd = 220 and osr.create_date is not null then osr.create_date end) as Ordered,
  max(case when osr.order_status_cd = 300 and osr.create_date is not null then osr.create_date end) as Shipped,
  max(case when osr.order_status_cd = 400 and osr.create_date is not null then osr.create_date end) as Received,
  max(case when osr.order_status_cd = 500 and osr.create_date is not null then osr.create_date end) as Completed,
from order_status_record osr
inner join msorder mo 
  on mo.order_id = osr.msorder_id
group by mo.order_id