Query of multiple counts with conditions or multiple querys

Question

I have this demo table
create table qtyrtu
rtunam varchar2(10) not null,
entity varchar2(10) not null,
linked number(3) not null
Insert into qtyrtu values ('02vh1', 'zdvh', 100);
Insert into qtyrtu values ('02vh2', 'zdvh', 0);
Insert into qtyrtu values ('02eh1', 'zdvh', 0);
Insert into qtyrtu values ('02sh1', 'stvh', 100);
Insert into qtyrtu values ('02sh1', 'stvh', 0);
Insert into qtyrtu values ('02sh1', 'stvh', 100);
Insert into qtyrtu values ('02tx', 'zdch', 100);
Insert into qtyrtu values ('02ta', 'zdch', 100);And my result expected would be the next one.
Entity | Count(rtunam linked by 100) | Count (rtunam linked by 0)
STVH    2   1
ZDCH    2   0   
ZDVH    1   2The problem is that I don't know how to query the 0, when I do my query(by column) it shows this:
select entity, count(rtunam) from qtyrtu where linked = 100 group by entity order by entity asc;
STVH    2
ZDCH    2   
ZDVH    1
select entity, count(rtunam) from qtyrtu where linked = 0group by entity order by entity asc;
STVH     1
ZDVH     2And I need to show all the counts( even the 0)
Regards

Answer 1

Hi,
Thanks for posting the sample data and the results; that really helps!
Here's one way:
SELECT    UPPER (entity)                    AS upper_entity
,       COUNT (CASE WHEN linked = 100 THEN 1 END)     AS cnt_100
,       COUNT (CASE WHEN linked = 0   THEN 1 END)     AS cnt_0
FROM       qtyrtu
GROUP BY  entity
;It looks like rtunam plays no role in this problem: is that right?
You already know how to get the separate column results, using a WHERE clause to ignore certain rows, but you can't use a WHERE clause here, because to want to ignore different rows for the two COUNT columns. A CASE expression can be like a WHERE clause that applies only to one column.