Column count based on a condition

Question

I have created an oracle query like as shown below,the query is working fine but the problem is that I want one more column which is the count of name where category should be A and id should be 1

SELECT name, velocity, COUNT(*) AS count, category FROM section GROUP BY name, velocity

Can anyone please tell me some solution for this

Answer 1

SELECT name, velocity, COUNT(*) AS count, 
COUNT(CASE WHEN category = 'A' AND id = 1 THEN 1 END)
FROM section 
GROUP BY name, velocity

This should work.

If record does not meet the condition then it will return a NULL, and count skips NULL fields.

Answer 2

Something like this:

SELECT name, velocity, COUNT(*) AS count, 
SUM(CASE WHEN category = 'A' AND id = 1 THEN 1 ELSE 0 END)
FROM section 
GROUP BY name, velocity