Distinct records based on condition within a table

Question

Hello PL/SQL Gurus/experts,
I am using Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production version
I have following table -
Note - Table don't have any primary key on Order_ID -
DROP TABLE T;
create table T(Order_ID,Active_Flg) as select
'201002', 'Y' from dual union all select
'201002', '' from DUAL union all select
'201003', '' from dual union all select
'201004', 'Y' from DUAL union all select
'201004', '' from dual union all select
'201005', '' from DUAL ;I want to fetch those Order_ID which have Active-Flg as NULL and don't have the entry for Active_Flg=Y
If use the following then it returns the distinct Order_ID but not the expected one -
SELECT DISTINCT ORDER_ID FROM T WHERE ACTIVE_FLG IS NULL;Result -
ORDER_ID
201004
201002
201003
201005Kindly help.....

Answer 1

try this
with t as
select
'201002' order_id, 'Y' active_flg from dual union all select
'201002', '' from DUAL union all select
'201003', '' from dual union all select
'201004', 'Y' from DUAL union all select
'201004', '' from dual union all select
'201005', '' from DUAL
select order_id
  from (
          select
            order_id,
            active_flg,
            count(case when active_flg =  'Y' then 1 end) over(partition by order_id) cntY
          from t
where cntY = 0 and active_flg is null