How do I use the CASE statement in the where clause?

Question

Hello Everyone,
I have 2 queries that do what I need to do but I am trying to learn how to use the CASE statement.
I have tried to combine these 2 into one query using a case statement but don't get the results I need.
Could use some help on how to use the case syntax to get the results needed.
thanks a lot
select segment_name,
product_type,
count (distinct account_id)
FROM NL_ACCT
where
ind = 'N'
and
EM_ind = 'N'
and product_type in ('TAX','PAY')
and acct_open_dt between (cast('2006-01-17' as date)) and (cast('2006-01-17' as date) + 60)
GROUP BY 1,2
order by product_type
select segment_name,
product_type,
count (distinct account_id)
FROM NL_ACCT
where
ind = 'N'
and
EM_ind = 'N'
and product_type not in ('TAX','PAY')
and acct_open_dt between (cast('2006-01-17' as date)) and (cast('2006-01-17' as date) + 30)
group by 1,2
order by product_type

Answer 1

Something like:
SELECT segment_name, product_type,
       SUM(CASE WHEN account_id IN ('TAX','PAY') and
                     acct_open_dt BETWEEN TO_DATE('2006-01-17', 'yyyy-mm-dd') and
                           TO_DATE('2006-01-17', 'yyyy-mm-dd') + 60 THEN 1
                ELSE 0 END) tax_pay,
       SUM(CASE WHEN account_id NOT IN ('TAX','PAY') and
                     acct_open_dt BETWEEN TO_DATE('2006-01-17', 'yyyy-mm-dd') and
                           TO_DATE('2006-01-17', 'yyyy-mm-dd') + 30 THEN 1
                ELSE 0 END) not_tax_pay
FROM NL_ACCT
WHERE ind = 'N' and
      em_ind = 'N' and
      acct_open_dt BETWEEN TO_DATE('2006-01-17', 'yyyy-mm-dd') and
                           TO_DATE('2006-01-17', 'yyyy-mm-dd') + 60
GROUP BY segment_name, product_type
ORDER BY product_typeNote: You cannor GROUP BY 1,2, you need to explicitly name the columns to group by.
HTH
John